WO2002073410A2 - System and method for synchronizing a data copy using an accumulation remote copy trio - Google Patents

System and method for synchronizing a data copy using an accumulation remote copy trio Download PDF

Info

Publication number
WO2002073410A2
WO2002073410A2 PCT/US2002/005582 US0205582W WO02073410A2 WO 2002073410 A2 WO2002073410 A2 WO 2002073410A2 US 0205582 W US0205582 W US 0205582W WO 02073410 A2 WO02073410 A2 WO 02073410A2
Authority
WO
WIPO (PCT)
Prior art keywords
volume
copy
data
source
data file
Prior art date
Application number
PCT/US2002/005582
Other languages
French (fr)
Other versions
WO2002073410A3 (en
Inventor
David G. Hostetter
Michael S. Milillo
Christopher J. West
Robert P. Eksenberry
Original Assignee
Storage Technology Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Storage Technology Corporation filed Critical Storage Technology Corporation
Priority to AU2002244140A priority Critical patent/AU2002244140A1/en
Publication of WO2002073410A2 publication Critical patent/WO2002073410A2/en
Publication of WO2002073410A3 publication Critical patent/WO2002073410A3/en

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/16—Error detection or correction of the data by redundancy in hardware
    • G06F11/20—Error detection or correction of the data by redundancy in hardware using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements
    • G06F11/2053—Error detection or correction of the data by redundancy in hardware using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements where persistent mass storage functionality or persistent mass storage control functionality is redundant
    • G06F11/2056—Error detection or correction of the data by redundancy in hardware using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements where persistent mass storage functionality or persistent mass storage control functionality is redundant by mirroring
    • G06F11/2082—Data synchronisation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/20—Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
    • G06F16/27—Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S707/00—Data processing: database and file management or data structures
    • Y10S707/964—Database arrangement
    • Y10S707/966—Distributed
    • Y10S707/967—Peer-to-peer
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S707/00—Data processing: database and file management or data structures
    • Y10S707/99951—File or database maintenance
    • Y10S707/99952—Coherency, e.g. same view to multiple users
    • Y10S707/99953—Recoverability
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S707/00—Data processing: database and file management or data structures
    • Y10S707/99951—File or database maintenance
    • Y10S707/99952—Coherency, e.g. same view to multiple users
    • Y10S707/99955—Archiving or backup

Definitions

  • the present invention relates generally to a system and method for synchronizing a remote data copy and, more particularly, to a system and method for efficient snapshot synchronization of a data copy using an accumulation remote copy trio including a source volume, accumulated write commands, and an established peer-to-peer remote copy (PPRC) volume pair.
  • PPRC peer-to-peer remote copy
  • peer-to-peer remote copy is a synchronous copy mechanism that creates a copy of data at a remote or secondary storage system.
  • the copy at the secondary storage is kept current with the data located at the primary storage system.
  • a copy of the data located at the secondary storage system is kept in synch with the data at the primary storage system as observed by the user of the data.
  • Volume pairs are designated in which a volume in the primary storage system is paired with a volume in the secondary storage system.
  • Data transfer occurs in pairs in which data is transferred from a volume in a primary storage system to a corresponding volume in a secondary storage system, which together may be referred to as an established PPRC pair.
  • a data copy made to the secondary, or "recovery,” storage system occurs synchronously from a host point of view with write operations to volumes in the primary storage system.
  • the data written to a particular volume is also written to a corresponding volume in the secondary storage system using a path to the secondary storage system.
  • Effecting a data copy from a primary volume to a secondary volume in a PPRC system may include an internal snapshot copying mechanism for copying all of the data of a source storage volume to a primary storage volume in a PPRC pair, which data is then migrated to the corresponding secondary storage volume.
  • the internal snapshot copying mechanism makes a copy of at least one pointer to the data of a source volume, and the primary volume in the PPRC pair uses the pointers to access the data.
  • the internal snapshot copying mechanism makes a copy of the data of a source volume to a primary volume of a PPRC pair by using pointers to the data in the source volume and then storing the pointers in a map. By using pointers, the internal snapshot mechanism can quickly copy the data from the source volume without affecting the access of a host to the source volume. The primary volume then transfers the data to the corresponding secondary volume without any host access interruption to the source volume.
  • a duplex pending pair is a pair of corresponding volume pairs in which the system is attempting to copy the primary storage volume to the secondary storage volume.
  • a duplex state pair is a pair of corresponding volume pairs in which the data from the primary storage volume has been copied to the secondary storage volume.
  • individual primary volume performance may be additionally affected because the host has to compete with the synchronizing task for access to the source volume.
  • the synchronizing task is the process of migrating the source storage volume to the secondary storage volume.
  • Such a system and method would preferably employ a group of three storage volumes in this operation.
  • the first would be the source volume of the snapshot copy, which would accumulate the write commands in a bitmap.
  • the next would be the target volume of the snapshot copy, which would be a primary volume of a PPRC pair and would receive the results of the write commands and a copy of the bitmap having the accumulated write commands.
  • the final volume would be on the secondary system and would be the secondary volume of the PPRC pair.
  • the three volumes would together comprise an accumulation remote copy trio.
  • the source volume could be specified along with the establishment of the primary target- secondary PPRC pair, or configured through an operations panel. Upon establishment of the PPRC pair, an internal snapshot copy would synchronize the source and primary target volumes.
  • the primary target volume would begin synchronization with the secondary volume by sending over the entire volume.
  • the source volume would establish a bitmap and begin accumulating write commands received from a host. Subsequent snapshot copies from the source volume to the primary target volume would only snapshot copy the accumulated write commands. Only those accumulated write commands would then be migrated to the secondary volume.
  • Such a system and method would thereby allow a user to make a point-in-time copy of data and very efficiently migrate that copy to a secondary system without impacting the source volume.
  • the target of the snapshot copy would be the primary of a PPRC pair that would transfer only the tracks specified in the bitmap to the secondary volume. In such a fashion, the PPRC pair would become duplex much more efficiently because only the specified tracks in the bitmap would be sent to the secondary volume.
  • the bitmap could represent granularity at a record, track or cylinder level.
  • Such a system and method would thereby remove host impact to the source volume while data is being migrated to the secondary volume. As a result, very little response time degradation would be seen by the host. Still further, the more efficient migration of data to the secondary volume would reduce the time it takes to synchronize the volumes, consume less system resources, and reduce the time interval between potential snapshot copies for migration purposes.
  • a system for synchronizing a data copy.
  • the system comprises a source storage volume having a data file stored thereon, the source volume for receiving a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands.
  • the system further comprises a secondary storage volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the
  • the system may also comprise a primary target storage volume for receiving the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record to the secondary volume
  • a method for synchronizing a data copy.
  • the method comprises storing a data file on a source storage volume, receiving at the source volume a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands.
  • the method further comprises storing a copy of the data file on a secondary storage volume, receiving at the secondary volume data indicated by the write command record, and storing the data indicated by the write command record on the secondary volume, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file.
  • the method may also comprise receiving at a primary target storage volume the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record from the target volume to the secondary volume.
  • a method for synchronizing a data copy comprising providing a source storage volume having a data file stored thereon, the source volume for receiving a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands.
  • the method further comprises providing a secondary storage volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the write command record, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file.
  • the method may also comprise providing a primary target storage volume for receiving the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record to the secondary storage volume.
  • FIG. 1 illustrates a block diagram of a peer-to-peer remote copy (PPRC) system according to the prior art
  • FIG. 2 illustrates a block diagram of the accumulation remote copy trio architecture according to the present invention, including a source volume, target volume, and secondary volume;
  • FIG. 3 illustrates a simplified, representative flow chart of the method for efficient snapshot synchronization according to the present invention.
  • peer-to-peer remote copy is a synchronous copy mechanism that creates a copy of data at a remote or secondary storage system.
  • volume pairs are designated in which a storage volume in the primary system is paired with a storage volume in the secondary system, which together may be referred to as an established PPRC volume pair.
  • a data copy made to the secondary system occurs synchronously from a host point of view with write operations to volumes in the primary system.
  • PPRC system 10 When data is written to the primary storage system, the data written to a particular volume is also written to a corresponding volume in the secondary storage system using a path to the secondary storage system.
  • PPRC system 10 includes a primary storage system 12 and a secondary storage system 14.
  • PPRC system further includes a host 16 connected to primary storage system 12.
  • Host 16 stores data in primary storage system 12.
  • Data written to primary storage system 12 is copied to secondary storage system 14.
  • the copy process creates a copy of the data from primary storage system 12 into secondary storage system 14.
  • the copy process is a PPRC mechanism.
  • a write made by host 16 is considered complete only after the data written to primary storage system 12 also is written to secondary storage system 14.
  • Host 16 may take various forms, such as a server on a network, a Web server on the Internet, or a mainframe computer.
  • Primary storage system 12 and secondary storage system 14 are disk systems in these examples, although tape or other storage systems known in the art may also be used.
  • a communication path 32 connects host 16 to primary storage system
  • a communication path 36 connects primary storage system 12 with secondary storage system 14.
  • Communication paths 32 and 36 may take various forms, such as, for example, a local area network (LAN), a wide area network (WAN), the Internet, or an intranet.
  • Communication paths 32 and 36 contain various links, such as, for example, fiber optic lines, packet switched communication links, enterprise systems connection (ESCON) fibers, small computer system interface (SCSI) cable, and wireless communication links.
  • LAN local area network
  • WAN wide area network
  • the Internet or an intranet.
  • Communication paths 32 and 36 contain various links, such as, for example, fiber optic lines, packet switched communication links, enterprise systems connection (ESCON) fibers, small computer system interface (SCSI) cable, and wireless communication links.
  • ESCON enterprise systems connection
  • SCSI small computer system interface
  • PPRC system 10 is intended as an example of a data processing system and not as an architectural limitation to the present invention.
  • host 16 and primary storage system 12 may be connected directly, while primary storage system 12 and secondary storage system 14 may be connected by a LAN or a WAN.
  • primary storage system 12 and secondary storage system 14 may be connected to each other by a network rather than a direct connection.
  • Primary storage system 12 includes a set of storage volumes 20, 22, and 24.
  • Secondary storage system 14 includes a set of storage volumes 26, 28, and 30. Secondary storage volumes 26, 28, and 30 correspond to primary storage volumes 20, 22, and 24.
  • the correspondence between the volumes in primary and secondary storage systems 12 and 14 is set up in PPRC pairs, such that a storage volume in primary storage system 12 has a corresponding storage volume in secondary storage system 14. For instance, primary volume 20 is paired with secondary volume 26, primary volume 22 is paired with secondary volume 28, and primary volume 24 is paired with secondary volume 30. These pairs are referred to as established PPRC pairs.
  • primary storage system 12 sends data over communication path 36 to secondary storage system 14 each time data is written to a primary storage volume by host 16.
  • Secondary storage system 14 then copies the data to the secondary storage volume corresponding to the primary storage volume. For example, if data is written to primary storage volume 20 then the data is copied to the corresponding secondary storage volume 26.. Similarly, if data is written to primary storage volume 22 then the data is copied to the corresponding secondary storage volume 28.
  • FIG. 40 a block diagram of the preferred accumulation remote copy trio architecture according to the present invention is shown, denoted generally by reference numeral 40.
  • a host 42 is provided in communication with primary storage subsystem 44 via communication path 46.
  • Primary storage subsystem 44 is also provided in communication with a secondary storage subsystem 48 via communication path 50.
  • Primary storage subsystem 44 includes a source storage volume 52, which is provided in communication with a primary target storage volume 54.
  • Secondary storage subsystem 48 includes a secondary storage volume 56, which together with primary target storage volume 54 comprise an established PPRC volume pair as previously described.
  • Source volume 52, primary target volume 54, and secondary volume 56 together comprise the preferred accumulation remote copy trio.
  • Figure 2 depicts a single PPRC volume pair (primary target volume 54 and secondary volume 56) and a single source volume 52 for the sake of simplicity only. As those of ordinary skill will appreciate, additional PPRC volume pairs and source volumes may also be included.
  • Primary storage subsystem 44 and secondary storage subsystem 48 are disk systems in these examples, although tape or other storage systems known in the art may also be used.
  • communication paths 46 and 50 may take various forms, such as, for example, a local area network (LAN), a wide area network (WAN), the Internet, or an intranet.
  • Communication paths 46 and 50 contain various links, such as, for example, fiber optic lines, packet switched communication links, enterprise systems connection (ESCON) fibers, small computer system interface (SCSI) cable, and wireless communication links.
  • the architecture 40 depicted in Figure 2 is intended as an example of a system in which the present invention may be implemented and not as an architectural limitation to the present invention.
  • host 42 and primary storage system 44 may be connected directly, while primary storage system 44 and secondary storage system 48 may be connected by a LAN or a WAN. Further, primary storage system 44 and secondary storage system 48 may be connected to each other by a network rather than a direct connection.
  • making a data copy from source volume 52 to secondary volume 56 in a PPRC system may be accomplished by an internal snapshot copying mechanism for copying all of the data of source volume 52 to primary target volume 54, which data is then migrated to corresponding secondary volume 56.
  • the internal snapshot copying mechanism makes a copy of a pointer to the data of source volume 52, and the primary target volume 54 in the PPRC pair uses the pointers to access the data.
  • the internal snapshot copying mechanism makes a copy of the data of source volume 52 to primary target volume 54 of the PPRC pair by using pointers to the data in the source volume 52 and then storing the pointers in a map (not shown).
  • the internal snapshot mechanism can quickly copy the data from the source volume 52 without affecting the access of host 42 to the source volume 52.
  • the primary target volume 54 then transfers the data to the corresponding secondary volume 56 via communication path 50 without any interruption of access by host 42 to source volume 52.
  • the present invention provides an improved system and method for synchronizing a data copy which overcomes these problems.
  • a user wants to snapshot copy from simplex source volume 52 to PPRC volume pair 54, 56 in order to migrate backup data to secondary subsystem 48, rather than sending the entire source volume 52 to the secondary volume 56, only accumulated write commands received by source volume 52 from host 42 are sent.
  • Source volume 52 could be specified along with the establishment of the primary target-secondary PPRC pair 54, 56. Alternatively, source volume 52 could be configured through an operations panel.
  • an internal snapshot copy is used to synchronize the source 52 and primary target 54 volumes.
  • the primary target volume 54 begins synchronization with the secondary volume 56 by sending over the entire volume.
  • source volume 52 has a data file (not shown) stored thereon. In that regard, a single data file is discussed herein for the sake of simplicity only. As is well known to those of ordinary skill in the art, source volume 52 may comprise any number of data files.
  • Source volume 52 receives a series of write commands from host 42 via communication path 46, which source volume 52 may execute in order to generate an updated data file (not shown).
  • source volume 52 In order to make the snapshot copying and the migration of the data efficient, source volume 52 generates a record of the series of write commands received from host 42, preferably by establishing a bitmap 58 which is used to signify the accumulated write commands.
  • both primary target volume 54 and secondary volume 56 have stored thereon a copy of the data file stored on source volume 52.
  • Subsequent snapshot copies from source volume 52 to primary target volume 54 snapshot copy only the write command record.
  • a copy 60 of bitmap 58 having the accumulated write commands is received by primary target volume 54 from source volume 52.
  • Bitmap 58 is then reset at the source volume in order to identify the next set of accumulated write commands.
  • Primary target volume 54 also receives from source volume 52 the data of the write commands from host 42. Only the accumulated write commands, however, are then migrated to secondary volume 56 from primary target volume 54. That is, secondary volume 56 receives and stores the data indicated by the copy 60 of the write command record.
  • the copy of the data file (not shown) and the data indicated by the copy of the write command record 60 may be used by the secondary volume 56 in a data recovery operation to generate a copy of the updated data file stored on source volume 52 in the event of a disaster.
  • the present invention thereby allows a user to make a point-in-time copy of data and very efficiently migrate that copy to a secondary system 48 without impacting the source volume 52.
  • the target volume 54 of the snapshot copy is the primary of a PPRC volume pair that transfers only the records, tracks or cylinders specified in the bitmap 58, 60 to the secondary volume 56.
  • the PPRC pair 54, 56 become duplex much more efficiently because only the specified records, tracks or cylinders in the bitmap 58, 60 are sent to the secondary volume 56.
  • the present invention thereby removes host 42 impact to the source volume 52 while data is being migrated to the secondary volume 56. As a result, very little response time degradation is seen by host 42. Still further, the more efficient migration of data to secondary volume 56 reduces the time it takes to synchronize the volumes 52, 56, consumes less system resources, and reduces the time interval between potential snapshot copies for migration purposes.
  • the present invention provides a method for synchronizing a data copy comprising storing 72 a data file on a source storage volume, receiving 74 at the source volume a series of write commands from a host, executing 76 the series of write commands to generate an updated data file, and generating 78 a record of the series of write commands.
  • the method may further include receiving 80 at a primary target storage volume a copy of the data file and a copy of the write command record from the source volume, and transmitting 82 a copy of tlie data file and data indicated by the write command record from the primary target volume to the secondary volume.
  • the write command record is reset at the source volume in order to identify the next group of accumulated write commands.
  • the method further comprises storing 84 a copy of the data file on a secondary storage volume, receiving 86 at the secondary volume data indicated by the write command record, and storing 88 the data indicated by the write command record on the secondary volume, wherein the copy of the data file and the data indicated by write command record are available for use in generating a copy of the updated data file.
  • the method 70 depicted in Figure 3 is but one embodiment of the present invention.
  • the steps of method 70 may be executed in sequences other than that shown in Figure 3, which is exemplary only, including the execution of one or more steps simultaneously.
  • one or more of the steps of method 70 illustrated in Figure 3 may be omitted without departing from the scope of the present invention, such as, for example, receiving 80 at a primary target storage volume a copy of the data file and data indicated by the write command record from the source volume, and transmitting 82 the copy of the data file and the data indicated by the write command record from the primary target volume to the secondary volume.
  • the present invention when a user wants to snapshot copy from a simplex source volume to a PPRC volume pair in order to migrate backup data to a secondary system, rather than sending the entire source volume to the secondary volume, only accumulated write commands are sent.
  • a bitmap is used to signify the accumulated write commands (i.e. , the write command record).
  • the present invention preferably employs a group of three storage volumes which together comprise an accumulation remote copy trio.
  • the trio includes a source volume which accumulates the write commands in a bitmap, a primary target volume which receives the write commands and a copy of the bitmap having the accumulated write commands, and a secondary volume.
  • a source volume which accumulates the write commands in a bitmap
  • a primary target volume which receives the write commands and a copy of the bitmap having the accumulated write commands
  • a secondary volume Upon establishment of the primary target and the secondary as a PPRC volume pair, an internal snapshot copy synchronizes the source and the primary target volumes.
  • the primary target volume begins synchronization with the secondary volume by sending over the entire volume.
  • the source volume establishes a bitmap and begins accumulating write commands received from a host. Subsequent snapshot copies from the source volume to the primary target volume snapshot copy only the accumulated write commands, as indicated by the write command record. Only those accumulated write commands are then migrated to the secondary volume.
  • the present invention allows a user to make a point- in-time copy of data and very efficiently migrate that copy to a secondary system without impacting the source volume.
  • the target of the snapshot copy is the primary of a PPRC pair that transfers only the tracks, records or cylinders specified in the bitmap to the secondary volume.
  • the PPRC pair therefore becomes duplex much more efficiently because only the specified tracks, records or cylinders in the bitmap are sent to the secondary volume.
  • the present invention thereby removes host impact to the source volume while data is being migrated to the secondary volume. As a result, very little response time degradation is seen by the host. Still further, the more efficient migration of data to the secondary volume reduces the time it takes to synchronize the volumes, consumes less system resources, and reduces the time interval between potential snapshot copies for migration purposes

Abstract

A system and method for synchronizing a data copy that include a source volume having a data file stored thereon (72), the source volume for receiving write commands from a host (74), executing the write commands to generate an updated data file (76), and generating a record of the write commands (78). The system and method further include a secondary volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the write command record (82), wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file.

Description

SYSTEM AND METHOD FOR
SYNCHRONIZING A DATA COPY USING
AN ACCUMULATION REMOTE COPY TRIO
Technical Field
The present invention relates generally to a system and method for synchronizing a remote data copy and, more particularly, to a system and method for efficient snapshot synchronization of a data copy using an accumulation remote copy trio including a source volume, accumulated write commands, and an established peer-to-peer remote copy (PPRC) volume pair.
Background Art
With increasingly large amounts of data being handled in data processing systems, storage systems, such as disk or tape storage systems, are being used to store data. Some organizations rely heavily on data and quick access to the data. Disasters caused by environmental conditions, user errors, or application errors may occur in which access to the data is lost for some period of time. Mirroring or copying data to a secondary storage system from a primary storage system is currently employed for recovery purposes to minimize the time in which access to data is lost due to such a disaster.
In that regard, peer-to-peer remote copy (PPRC) is a synchronous copy mechanism that creates a copy of data at a remote or secondary storage system. The copy at the secondary storage is kept current with the data located at the primary storage system. In other words, a copy of the data located at the secondary storage system is kept in synch with the data at the primary storage system as observed by the user of the data. Volume pairs are designated in which a volume in the primary storage system is paired with a volume in the secondary storage system. Data transfer occurs in pairs in which data is transferred from a volume in a primary storage system to a corresponding volume in a secondary storage system, which together may be referred to as an established PPRC pair. With a PPRC system, a data copy made to the secondary, or "recovery," storage system occurs synchronously from a host point of view with write operations to volumes in the primary storage system. When data is written to the primary storage system, the data written to a particular volume is also written to a corresponding volume in the secondary storage system using a path to the secondary storage system.
Effecting a data copy from a primary volume to a secondary volume in a PPRC system may include an internal snapshot copying mechanism for copying all of the data of a source storage volume to a primary storage volume in a PPRC pair, which data is then migrated to the corresponding secondary storage volume. The internal snapshot copying mechanism makes a copy of at least one pointer to the data of a source volume, and the primary volume in the PPRC pair uses the pointers to access the data. The internal snapshot copying mechanism makes a copy of the data of a source volume to a primary volume of a PPRC pair by using pointers to the data in the source volume and then storing the pointers in a map. By using pointers, the internal snapshot mechanism can quickly copy the data from the source volume without affecting the access of a host to the source volume. The primary volume then transfers the data to the corresponding secondary volume without any host access interruption to the source volume.
There is, however, a large time difference between snapshot copies and synchronizing remote copies. That is, if a user wants to migrate a point-in-time copy of data from a source volume to a secondary volume in a PPRC pair by snapshot copying the source volume to the primary volume in the PPRC pair, the entire source volume is sent to the secondary volume, an operation which can take a very long time.
Further, as the number of PPRC volume pairs that are established and attempt to move from a duplex pending to a duplex state increases, system resources become increasingly degraded as duplex pending pairs are added. Cache space, processor cycles, and data paths are consumed while duplex pending. A duplex pending pair is a pair of corresponding volume pairs in which the system is attempting to copy the primary storage volume to the secondary storage volume. A duplex state pair is a pair of corresponding volume pairs in which the data from the primary storage volume has been copied to the secondary storage volume. Moreover, individual primary volume performance may be additionally affected because the host has to compete with the synchronizing task for access to the source volume. The synchronizing task is the process of migrating the source storage volume to the secondary storage volume.
Thus, there is needed an improved system and method for synchronizing a data copy. In such a system and method, when a user wants to snapshot copy from a simplex source volume to a PPRC volume pair in order to migrate backup data to a secondary system, rather than sending the entire source volume to the secondary volume, only accumulated write commands would be sent. In order to make the snapshot copying and the migration of the data efficient, a bitmap would be used to signify the accumulated write commands. Advantageously, only those write commands would be snapshot copied and migrated to the secondary.
Such a system and method would preferably employ a group of three storage volumes in this operation. The first would be the source volume of the snapshot copy, which would accumulate the write commands in a bitmap. The next would be the target volume of the snapshot copy, which would be a primary volume of a PPRC pair and would receive the results of the write commands and a copy of the bitmap having the accumulated write commands. The final volume would be on the secondary system and would be the secondary volume of the PPRC pair. The three volumes would together comprise an accumulation remote copy trio. The source volume could be specified along with the establishment of the primary target- secondary PPRC pair, or configured through an operations panel. Upon establishment of the PPRC pair, an internal snapshot copy would synchronize the source and primary target volumes. The primary target volume would begin synchronization with the secondary volume by sending over the entire volume. The source volume would establish a bitmap and begin accumulating write commands received from a host. Subsequent snapshot copies from the source volume to the primary target volume would only snapshot copy the accumulated write commands. Only those accumulated write commands would then be migrated to the secondary volume.
Such a system and method would thereby allow a user to make a point-in-time copy of data and very efficiently migrate that copy to a secondary system without impacting the source volume. The target of the snapshot copy would be the primary of a PPRC pair that would transfer only the tracks specified in the bitmap to the secondary volume. In such a fashion, the PPRC pair would become duplex much more efficiently because only the specified tracks in the bitmap would be sent to the secondary volume. The bitmap could represent granularity at a record, track or cylinder level. Such a system and method would thereby remove host impact to the source volume while data is being migrated to the secondary volume. As a result, very little response time degradation would be seen by the host. Still further, the more efficient migration of data to the secondary volume would reduce the time it takes to synchronize the volumes, consume less system resources, and reduce the time interval between potential snapshot copies for migration purposes.
Summary of the Invention
Accordingly, it is an object of the present invention to provide an improved system and method for synchronizing a data copy.
According to the present invention, then, a system is provided for synchronizing a data copy. The system comprises a source storage volume having a data file stored thereon, the source volume for receiving a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands. The system further comprises a secondary storage volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the
; write command record, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file. The system may also comprise a primary target storage volume for receiving the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record to the secondary volume
Still further according to the present invention, a method is also provided for synchronizing a data copy. The method comprises storing a data file on a source storage volume, receiving at the source volume a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands. The method further comprises storing a copy of the data file on a secondary storage volume, receiving at the secondary volume data indicated by the write command record, and storing the data indicated by the write command record on the secondary volume, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file. The method may also comprise receiving at a primary target storage volume the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record from the target volume to the secondary volume.
According to the present invention, a method is also provided for synchronizing a data copy comprising providing a source storage volume having a data file stored thereon, the source volume for receiving a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands. The method further comprises providing a secondary storage volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the write command record, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file. The method may also comprise providing a primary target storage volume for receiving the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record to the secondary storage volume. The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the present invention when taken in connection with the accompanying drawings.
Brief Description of the Drawings
FIG. 1 illustrates a block diagram of a peer-to-peer remote copy (PPRC) system according to the prior art;
FIG. 2 illustrates a block diagram of the accumulation remote copy trio architecture according to the present invention, including a source volume, target volume, and secondary volume; and
FIG. 3 illustrates a simplified, representative flow chart of the method for efficient snapshot synchronization according to the present invention.
Best Modes For Carrying Out The Invention
With reference to Figures 1-3, the preferred embodiment of the method and system of the present invention will now be described in greater detail.
As previously noted, it is common to copy data from a primary storage system to a secondary storage system for recovery purposes in the event of a disaster. In that regard, peer-to-peer remote copy (PPRC) is a synchronous copy mechanism that creates a copy of data at a remote or secondary storage system. In a PPRC system, volume pairs are designated in which a storage volume in the primary system is paired with a storage volume in the secondary system, which together may be referred to as an established PPRC volume pair. A data copy made to the secondary system occurs synchronously from a host point of view with write operations to volumes in the primary system. When data is written to the primary storage system, the data written to a particular volume is also written to a corresponding volume in the secondary storage system using a path to the secondary storage system. Referring now to Figure 1 , a block diagram of a peer-to-peer remote copy (PPRC) system according to the prior art is shown, denoted generally by reference numeral 10. As seen therein, PPRC system 10 includes a primary storage system 12 and a secondary storage system 14. PPRC system further includes a host 16 connected to primary storage system 12. Host 16 stores data in primary storage system 12. Data written to primary storage system 12 is copied to secondary storage system 14. The copy process creates a copy of the data from primary storage system 12 into secondary storage system 14. The copy process is a PPRC mechanism. In PPRC system 10, a write made by host 16 is considered complete only after the data written to primary storage system 12 also is written to secondary storage system 14. Host 16 may take various forms, such as a server on a network, a Web server on the Internet, or a mainframe computer. Primary storage system 12 and secondary storage system 14 are disk systems in these examples, although tape or other storage systems known in the art may also be used.
A communication path 32 connects host 16 to primary storage system
12. A communication path 36 connects primary storage system 12 with secondary storage system 14. Communication paths 32 and 36 may take various forms, such as, for example, a local area network (LAN), a wide area network (WAN), the Internet, or an intranet. Communication paths 32 and 36 contain various links, such as, for example, fiber optic lines, packet switched communication links, enterprise systems connection (ESCON) fibers, small computer system interface (SCSI) cable, and wireless communication links.
PPRC system 10 is intended as an example of a data processing system and not as an architectural limitation to the present invention. For example, host 16 and primary storage system 12 may be connected directly, while primary storage system 12 and secondary storage system 14 may be connected by a LAN or a WAN. Further, primary storage system 12 and secondary storage system 14 may be connected to each other by a network rather than a direct connection.
Primary storage system 12 includes a set of storage volumes 20, 22, and 24. Secondary storage system 14 includes a set of storage volumes 26, 28, and 30. Secondary storage volumes 26, 28, and 30 correspond to primary storage volumes 20, 22, and 24. The correspondence between the volumes in primary and secondary storage systems 12 and 14 is set up in PPRC pairs, such that a storage volume in primary storage system 12 has a corresponding storage volume in secondary storage system 14. For instance, primary volume 20 is paired with secondary volume 26, primary volume 22 is paired with secondary volume 28, and primary volume 24 is paired with secondary volume 30. These pairs are referred to as established PPRC pairs.
In operation, primary storage system 12 sends data over communication path 36 to secondary storage system 14 each time data is written to a primary storage volume by host 16. Secondary storage system 14 then copies the data to the secondary storage volume corresponding to the primary storage volume. For example, if data is written to primary storage volume 20 then the data is copied to the corresponding secondary storage volume 26.. Similarly, if data is written to primary storage volume 22 then the data is copied to the corresponding secondary storage volume 28.
Referring next to Figure 2, a block diagram of the preferred accumulation remote copy trio architecture according to the present invention is shown, denoted generally by reference numeral 40. As seen therein, a host 42 is provided in communication with primary storage subsystem 44 via communication path 46. Primary storage subsystem 44 is also provided in communication with a secondary storage subsystem 48 via communication path 50. Primary storage subsystem 44 includes a source storage volume 52, which is provided in communication with a primary target storage volume 54. Secondary storage subsystem 48 includes a secondary storage volume 56, which together with primary target storage volume 54 comprise an established PPRC volume pair as previously described. Source volume 52, primary target volume 54, and secondary volume 56 together comprise the preferred accumulation remote copy trio. It should be noted that Figure 2 depicts a single PPRC volume pair (primary target volume 54 and secondary volume 56) and a single source volume 52 for the sake of simplicity only. As those of ordinary skill will appreciate, additional PPRC volume pairs and source volumes may also be included. Primary storage subsystem 44 and secondary storage subsystem 48 are disk systems in these examples, although tape or other storage systems known in the art may also be used.
Once again, communication paths 46 and 50 may take various forms, such as, for example, a local area network (LAN), a wide area network (WAN), the Internet, or an intranet. Communication paths 46 and 50 contain various links, such as, for example, fiber optic lines, packet switched communication links, enterprise systems connection (ESCON) fibers, small computer system interface (SCSI) cable, and wireless communication links. Moreover, as noted above, the architecture 40 depicted in Figure 2 is intended as an example of a system in which the present invention may be implemented and not as an architectural limitation to the present invention. For example, host 42 and primary storage system 44 may be connected directly, while primary storage system 44 and secondary storage system 48 may be connected by a LAN or a WAN. Further, primary storage system 44 and secondary storage system 48 may be connected to each other by a network rather than a direct connection.
As noted above, according to the prior art, making a data copy from source volume 52 to secondary volume 56 in a PPRC system may be accomplished by an internal snapshot copying mechanism for copying all of the data of source volume 52 to primary target volume 54, which data is then migrated to corresponding secondary volume 56. The internal snapshot copying mechanism makes a copy of a pointer to the data of source volume 52, and the primary target volume 54 in the PPRC pair uses the pointers to access the data. The internal snapshot copying mechanism makes a copy of the data of source volume 52 to primary target volume 54 of the PPRC pair by using pointers to the data in the source volume 52 and then storing the pointers in a map (not shown). By using pointers, the internal snapshot mechanism can quickly copy the data from the source volume 52 without affecting the access of host 42 to the source volume 52. The primary target volume 54 then transfers the data to the corresponding secondary volume 56 via communication path 50 without any interruption of access by host 42 to source volume 52. As previously noted, however, there is a large time difference between snapshot copies and synchronizing remote copies. That is, if a user wants to migrate a point-in-time copy of data from source volume 52 to secondary volume 56 in the PPRC pair by snapshot copying the source volume 52 to the primary target volume 54 in the PPRC pair according to the prior art, the entire source volume 52 is sent to the secondary volume 56, an operation which can take a very long time. Further, as also previously noted, as the number of PPRC volume pairs that are established and attempt to move from a duplex pending to a duplex state increases, system resources become increasingly degraded as duplex pending pairs are added. Moreover, individual primary target volume 54 performance may be additionally affected because host 42 has to compete with the synchronizing task for access to source volume 52.
The present invention provides an improved system and method for synchronizing a data copy which overcomes these problems. According to the present invention, when a user wants to snapshot copy from simplex source volume 52 to PPRC volume pair 54, 56 in order to migrate backup data to secondary subsystem 48, rather than sending the entire source volume 52 to the secondary volume 56, only accumulated write commands received by source volume 52 from host 42 are sent. Source volume 52 could be specified along with the establishment of the primary target-secondary PPRC pair 54, 56. Alternatively, source volume 52 could be configured through an operations panel. Upon establishment of the PPRC pair 54, 56, an internal snapshot copy is used to synchronize the source 52 and primary target 54 volumes. The primary target volume 54 begins synchronization with the secondary volume 56 by sending over the entire volume.
Still referring to Figure 2, source volume 52 has a data file (not shown) stored thereon. In that regard, a single data file is discussed herein for the sake of simplicity only. As is well known to those of ordinary skill in the art, source volume 52 may comprise any number of data files. Source volume 52 receives a series of write commands from host 42 via communication path 46, which source volume 52 may execute in order to generate an updated data file (not shown). In order to make the snapshot copying and the migration of the data efficient, source volume 52 generates a record of the series of write commands received from host 42, preferably by establishing a bitmap 58 which is used to signify the accumulated write commands.
As a result of the initial snapshot copy operation described above, both primary target volume 54 and secondary volume 56 have stored thereon a copy of the data file stored on source volume 52. Subsequent snapshot copies from source volume 52 to primary target volume 54 snapshot copy only the write command record. In that regard, a copy 60 of bitmap 58 having the accumulated write commands is received by primary target volume 54 from source volume 52. Bitmap 58 is then reset at the source volume in order to identify the next set of accumulated write commands. Primary target volume 54 also receives from source volume 52 the data of the write commands from host 42. Only the accumulated write commands, however, are then migrated to secondary volume 56 from primary target volume 54. That is, secondary volume 56 receives and stores the data indicated by the copy 60 of the write command record. In that regard, the copy of the data file (not shown) and the data indicated by the copy of the write command record 60 may be used by the secondary volume 56 in a data recovery operation to generate a copy of the updated data file stored on source volume 52 in the event of a disaster.
The present invention thereby allows a user to make a point-in-time copy of data and very efficiently migrate that copy to a secondary system 48 without impacting the source volume 52. In that regard, the target volume 54 of the snapshot copy is the primary of a PPRC volume pair that transfers only the records, tracks or cylinders specified in the bitmap 58, 60 to the secondary volume 56. In such a fashion, the PPRC pair 54, 56 become duplex much more efficiently because only the specified records, tracks or cylinders in the bitmap 58, 60 are sent to the secondary volume 56. The present invention thereby removes host 42 impact to the source volume 52 while data is being migrated to the secondary volume 56. As a result, very little response time degradation is seen by host 42. Still further, the more efficient migration of data to secondary volume 56 reduces the time it takes to synchronize the volumes 52, 56, consumes less system resources, and reduces the time interval between potential snapshot copies for migration purposes.
Referring finally to Figure 3, a simplified, representative flow chart of the method for efficient snapshot synchronization according to the present invention is shown, denoted generally by reference numeral 70. As seen therein, the present invention provides a method for synchronizing a data copy comprising storing 72 a data file on a source storage volume, receiving 74 at the source volume a series of write commands from a host, executing 76 the series of write commands to generate an updated data file, and generating 78 a record of the series of write commands. The method may further include receiving 80 at a primary target storage volume a copy of the data file and a copy of the write command record from the source volume, and transmitting 82 a copy of tlie data file and data indicated by the write command record from the primary target volume to the secondary volume. In that regard, as previously noted, after the copy of the write command record is made to the primary target volume, the write command record is reset at the source volume in order to identify the next group of accumulated write commands. The method further comprises storing 84 a copy of the data file on a secondary storage volume, receiving 86 at the secondary volume data indicated by the write command record, and storing 88 the data indicated by the write command record on the secondary volume, wherein the copy of the data file and the data indicated by write command record are available for use in generating a copy of the updated data file.
It should be noted that the method 70 depicted in Figure 3 is but one embodiment of the present invention. In that regard, the steps of method 70 may be executed in sequences other than that shown in Figure 3, which is exemplary only, including the execution of one or more steps simultaneously. Similarly, one or more of the steps of method 70 illustrated in Figure 3 may be omitted without departing from the scope of the present invention, such as, for example, receiving 80 at a primary target storage volume a copy of the data file and data indicated by the write command record from the source volume, and transmitting 82 the copy of the data file and the data indicated by the write command record from the primary target volume to the secondary volume. As is readily apparent from the foregoing description, according to the present invention, when a user wants to snapshot copy from a simplex source volume to a PPRC volume pair in order to migrate backup data to a secondary system, rather than sending the entire source volume to the secondary volume, only accumulated write commands are sent. In order to make the snapshot copying and the migration of the data efficient, a bitmap is used to signify the accumulated write commands (i.e. , the write command record). Advantageously, only those write commands are snapshot copied and migrated to the secondary. To do so, the present invention preferably employs a group of three storage volumes which together comprise an accumulation remote copy trio. The trio includes a source volume which accumulates the write commands in a bitmap, a primary target volume which receives the write commands and a copy of the bitmap having the accumulated write commands, and a secondary volume. Upon establishment of the primary target and the secondary as a PPRC volume pair, an internal snapshot copy synchronizes the source and the primary target volumes. The primary target volume begins synchronization with the secondary volume by sending over the entire volume. The source volume establishes a bitmap and begins accumulating write commands received from a host. Subsequent snapshot copies from the source volume to the primary target volume snapshot copy only the accumulated write commands, as indicated by the write command record. Only those accumulated write commands are then migrated to the secondary volume.
In such a fashion, the present invention allows a user to make a point- in-time copy of data and very efficiently migrate that copy to a secondary system without impacting the source volume. The target of the snapshot copy is the primary of a PPRC pair that transfers only the tracks, records or cylinders specified in the bitmap to the secondary volume. The PPRC pair therefore becomes duplex much more efficiently because only the specified tracks, records or cylinders in the bitmap are sent to the secondary volume. The present invention thereby removes host impact to the source volume while data is being migrated to the secondary volume. As a result, very little response time degradation is seen by the host. Still further, the more efficient migration of data to the secondary volume reduces the time it takes to synchronize the volumes, consumes less system resources, and reduces the time interval between potential snapshot copies for migration purposes
Thus it is apparent that there has been provided, in accordance with the present invention, an unproved system and method for synchronizing a remote data copy. While the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.

Claims

What Is Claimed Is:
1. A system for synchronizing a data copy comprising: a source storage volume having a data file stored thereon, the source volume for receiving a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands; and a secondary storage volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the write command record, wherein the copy of the data file and the data indicated by write command record are available for use in generating a copy of the updated data file.
2. The system of claim 1 further comprising a target storage volume for receiving the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record to the secondary volume.
3. The system of claim 1 wherein the source and secondary volumes each comprise a magnetic tape.
4. The system of claim 1 wherein the source and secondary volumes each comprise a magnetic disk.
5. The system of claim 2 wherein the target and secondary volumes together comprise an established pair in a peer-to-peer remote copy system.
6. The system of claim 2 wherein the source, target and secondary volumes each comprise a magnetic tape.
7. The system of claim 2 wherein the source, target and secondary volumes each comprise a magnetic disk.
8. The system of claim 1 wherein the record of the series of write commands comprises a bitmap.
9. The system of claim 2 wherein the record of the series of write commands comprises a bitmap.
10. A method for synchronizing a data copy comprising: storing a data file on a source storage volume; receiving at the source volume a series of write commands from a host; executing the series of write commands to generate an updated data file; generating a record of the series of write commands; storing a copy of the data file on a secondary storage volume; receiving at the secondary volume data indicated by the write command record; and storing the data indicated by the write command record on the secondary volume, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data • file.
11. The method of claim 10 further comprising receiving at a target storage volume the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record from the target volume to the secondary volume.
12. The method of claim 10 wherein the source and secondary volumes each comprise a magnetic tape.
13. The method of claim 10 wherein the source and secondary volumes each comprise a magnetic disk.
14. The method of claim 11 wherein the target and secondary volumes together comprise an established pair in a peer-to-peer remote copy system.
15. The method of claim 11 wherein the source, target and secondary volumes each comprise a magnetic tape.
16. The method of claim 11 wherein the source, target and secondary volumes each comprise a magnetic disk.
17. The method of claim 10 wherein the record of the series of write commands comprises a bitmap.
18. The method of claim 11 wherein the record of the series of write commands comprises a bitmap.
19. A method for synchronizing a data copy comprising: providing a source storage volume having a data file stored thereon, the source volume for receiving a series of write commands from a host, executing the series of write commands to generate an updated data file, and generating a record of the series of write commands; and providing a secondary storage volume having a copy of the data file stored thereon, the secondary volume for receiving and storing data indicated by the write command record, wherein the copy of the data file and the data indicated by the write command record are available for use in generating a copy of the updated data file.
20. The method of claim 19 further comprising providing a target storage volume for receiving the copy of the data file and a copy of the write command record from the source volume, and transmitting the copy of the data file and the data indicated by the write command record to the secondary storage volume.
PCT/US2002/005582 2001-03-14 2002-02-26 System and method for synchronizing a data copy using an accumulation remote copy trio WO2002073410A2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2002244140A AU2002244140A1 (en) 2001-03-14 2002-02-26 System and method for synchronizing a data copy using an accumulation remote copy trio

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/805,503 US6728736B2 (en) 2001-03-14 2001-03-14 System and method for synchronizing a data copy using an accumulation remote copy trio
US09/805,503 2001-03-14

Publications (2)

Publication Number Publication Date
WO2002073410A2 true WO2002073410A2 (en) 2002-09-19
WO2002073410A3 WO2002073410A3 (en) 2003-10-16

Family

ID=25191737

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2002/005582 WO2002073410A2 (en) 2001-03-14 2002-02-26 System and method for synchronizing a data copy using an accumulation remote copy trio

Country Status (3)

Country Link
US (2) US6728736B2 (en)
AU (1) AU2002244140A1 (en)
WO (1) WO2002073410A2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106815091A (en) * 2015-11-27 2017-06-09 成都华为技术有限公司 Synchronous continuous transmission method, from end equipment and system

Families Citing this family (181)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6526418B1 (en) * 1999-12-16 2003-02-25 Livevault Corporation Systems and methods for backing up data files
WO2002057917A2 (en) * 2001-01-22 2002-07-25 Sun Microsystems, Inc. Peer-to-peer network computing platform
US6668264B1 (en) * 2001-04-03 2003-12-23 Network Appliance, Inc. Resynchronization of a target volume with a source volume
US6530003B2 (en) * 2001-07-26 2003-03-04 International Business Machines Corporation Method and system for maintaining data coherency in a dual input/output adapter utilizing clustered adapters
US6667022B2 (en) * 2001-08-14 2003-12-23 General Electric Co. Process for separating synthesis gas into fuel cell quality hydrogen and sequestration ready carbon dioxide
TWI241494B (en) * 2001-09-07 2005-10-11 Fen Peng Data storing and updating method for system document and device thereof
JP2005505045A (en) 2001-09-28 2005-02-17 コムヴォールト・システムズ・インコーポレーテッド Method and apparatus for creating and managing a quick recovery volume
US6681228B2 (en) * 2001-11-01 2004-01-20 Verisign, Inc. Method and system for processing query messages over a network
JP4168626B2 (en) * 2001-12-06 2008-10-22 株式会社日立製作所 File migration method between storage devices
US20030120699A1 (en) * 2001-12-24 2003-06-26 Storage Technology Corporation Variable synchronicity between duplicate transactions
US7266574B1 (en) * 2001-12-31 2007-09-04 Emc Corporation Identification of updated files for incremental backup
US7139932B2 (en) * 2002-01-03 2006-11-21 Hitachi, Ltd. Data synchronization of multiple remote storage after remote copy suspension
US6745303B2 (en) * 2002-01-03 2004-06-01 Hitachi, Ltd. Data synchronization of multiple remote storage
US7747576B2 (en) * 2002-02-20 2010-06-29 International Business Machines Corporation Incremental update control for remote copy
US7043738B2 (en) * 2002-03-05 2006-05-09 Sun Microsystems, Inc. Method and apparatus for managing a data imaging system using CIM providers in a distributed computer system
US20030177146A1 (en) * 2002-03-18 2003-09-18 International Business Machines Corporation Method, system, and program product for migrating data from one data base management system to another data base management system
JP4173673B2 (en) 2002-03-20 2008-10-29 株式会社日立製作所 File backup method and storage device
US7155501B2 (en) 2002-05-16 2006-12-26 Sun Microsystems, Inc. Method and apparatus for managing host-based data services using CIM providers
US7290045B2 (en) * 2002-07-01 2007-10-30 Sun Microsystems, Inc. Method and apparatus for managing a storage area network including a self-contained storage system
US7096330B1 (en) * 2002-07-29 2006-08-22 Veritas Operating Corporation Symmetrical data change tracking
US7171490B2 (en) * 2002-09-18 2007-01-30 Lucent Technologies Inc. Method and apparatus for reducing the number of write operations during route updates in pipelined forwarding engines
US20040054698A1 (en) * 2002-09-18 2004-03-18 Hitachi, Ltd. Layered computer system with thin clients
US6730883B2 (en) * 2002-10-02 2004-05-04 Stratagene Flexible heating cover assembly for thermal cycling of samples of biological material
US6938135B1 (en) 2002-10-04 2005-08-30 Veritas Operating Corporation Incremental backup of a data volume
EP1579331A4 (en) 2002-10-07 2007-05-23 Commvault Systems Inc System and method for managing stored data
US7664771B2 (en) * 2002-10-16 2010-02-16 Microsoft Corporation Optimizing defragmentation operations in a differential snapshotter
JP4136615B2 (en) * 2002-11-14 2008-08-20 株式会社日立製作所 Database system and database access method
US6910111B1 (en) 2002-12-20 2005-06-21 Veritas Operating Corporation Volume restoration using an accumulator map
US7447714B1 (en) 2003-02-25 2008-11-04 Storage Technology Corporation Management of multiple virtual data copies
JP2004259079A (en) * 2003-02-27 2004-09-16 Hitachi Ltd Data processing system
US7024530B2 (en) * 2003-03-14 2006-04-04 International Business Machines Corporation Method, system, and program for establishing and using a point-in-time copy relationship
US7318071B2 (en) * 2003-05-27 2008-01-08 Emc Corporation System and method for transfering data from a source machine to a target machine
US7133982B2 (en) * 2003-06-18 2006-11-07 International Business Machines Corporation Method, system, and article of manufacture for consistent copying of storage volumes
JP4124348B2 (en) 2003-06-27 2008-07-23 株式会社日立製作所 Storage system
JP2005309550A (en) * 2004-04-19 2005-11-04 Hitachi Ltd Remote copying method and system
JP4374953B2 (en) * 2003-09-09 2009-12-02 株式会社日立製作所 Data processing system
US7130975B2 (en) * 2003-06-27 2006-10-31 Hitachi, Ltd. Data processing system
US7664793B1 (en) * 2003-07-01 2010-02-16 Symantec Operating Corporation Transforming unrelated data volumes into related data volumes
US7165145B2 (en) * 2003-07-02 2007-01-16 Falconstor Software, Inc. System and method to protect data stored in a storage system
US7240080B2 (en) * 2003-07-30 2007-07-03 International Business Machines Corporation Method and apparatus for determining using least recently used protocol if one or more computer files should be written to one or more information storage media and synchronously providing one or more computer files between first and storage devices
US7219201B2 (en) * 2003-09-17 2007-05-15 Hitachi, Ltd. Remote storage disk control device and method for controlling the same
JP4598387B2 (en) 2003-09-17 2010-12-15 株式会社日立製作所 Storage system
US7287133B2 (en) 2004-08-24 2007-10-23 Symantec Operating Corporation Systems and methods for providing a modification history for a location within a data store
US7827362B2 (en) 2004-08-24 2010-11-02 Symantec Corporation Systems, apparatus, and methods for processing I/O requests
US7725760B2 (en) 2003-09-23 2010-05-25 Symantec Operating Corporation Data storage system
US7730222B2 (en) 2004-08-24 2010-06-01 Symantec Operating System Processing storage-related I/O requests using binary tree data structures
US7991748B2 (en) 2003-09-23 2011-08-02 Symantec Corporation Virtual data store creation and use
US7904428B2 (en) 2003-09-23 2011-03-08 Symantec Corporation Methods and apparatus for recording write requests directed to a data store
US7577806B2 (en) 2003-09-23 2009-08-18 Symantec Operating Corporation Systems and methods for time dependent data storage and recovery
US7278049B2 (en) * 2003-09-29 2007-10-02 International Business Machines Corporation Method, system, and program for recovery from a failure in an asynchronous data copying system
US7610318B2 (en) * 2003-09-29 2009-10-27 International Business Machines Corporation Autonomic infrastructure enablement for point in time copy consistency
US7133983B2 (en) 2003-09-29 2006-11-07 International Business Machines Corporation Method, system, and program for asynchronous copy
US7225208B2 (en) 2003-09-30 2007-05-29 Iron Mountain Incorporated Systems and methods for backing up data files
US7143122B2 (en) * 2003-10-28 2006-11-28 Pillar Data Systems, Inc. Data replication in data storage systems
WO2005050386A2 (en) 2003-11-13 2005-06-02 Commvault Systems, Inc. System and method for performing a snapshot and for restoring data
GB2423850B (en) 2003-11-13 2009-05-20 Commvault Systems Inc System and method for performing integrated storage operations
US7613785B2 (en) * 2003-11-20 2009-11-03 International Business Machines Corporation Decreased response time for peer-to-peer remote copy write operation
US8001085B1 (en) 2003-11-25 2011-08-16 Symantec Operating Corporation Remote data access for local operations
JP4412989B2 (en) 2003-12-15 2010-02-10 株式会社日立製作所 Data processing system having a plurality of storage systems
JP4477370B2 (en) * 2004-01-30 2010-06-09 株式会社日立製作所 Data processing system
US7412577B2 (en) 2004-02-05 2008-08-12 International Business Machines Corporation Shared data mirroring apparatus, method, and system
JP2005235058A (en) 2004-02-23 2005-09-02 Hitachi Ltd Snapshot acquisition method, snapshot acquisition device, and computer program provided with snapshot acquisition function
JP4483342B2 (en) * 2004-02-27 2010-06-16 株式会社日立製作所 System recovery method
JP4439960B2 (en) * 2004-03-22 2010-03-24 株式会社日立製作所 Storage device
US7343449B2 (en) 2004-03-22 2008-03-11 Hitachi, Ltd. Storage subsystem and storage system
US8336040B2 (en) 2004-04-15 2012-12-18 Raytheon Company System and method for topology-aware job scheduling and backfilling in an HPC environment
US9178784B2 (en) 2004-04-15 2015-11-03 Raytheon Company System and method for cluster management based on HPC architecture
US8335909B2 (en) 2004-04-15 2012-12-18 Raytheon Company Coupling processors to each other for high performance computing (HPC)
JP4382602B2 (en) * 2004-04-23 2009-12-16 株式会社日立製作所 Remote copy system
US7342555B2 (en) * 2004-04-30 2008-03-11 Microsoft Corporation Detecting low fidelity sync data
US7133989B2 (en) * 2004-05-05 2006-11-07 International Business Machines Corporation Point in time copy between data storage systems
US7461100B2 (en) * 2004-05-27 2008-12-02 International Business Machines Corporation Method for fast reverse restore
US7409510B2 (en) 2004-05-27 2008-08-05 International Business Machines Corporation Instant virtual copy to a primary mirroring portion of data
JP4575059B2 (en) * 2004-07-21 2010-11-04 株式会社日立製作所 Storage device
JP4519563B2 (en) 2004-08-04 2010-08-04 株式会社日立製作所 Storage system and data processing system
US7139782B2 (en) * 2004-09-21 2006-11-21 Hitachi, Ltd. Method of and system for testing remote storage
US20060080362A1 (en) * 2004-10-12 2006-04-13 Lefthand Networks, Inc. Data Synchronization Over a Computer Network
JP2006127028A (en) 2004-10-27 2006-05-18 Hitachi Ltd Memory system and storage controller
US8959299B2 (en) * 2004-11-15 2015-02-17 Commvault Systems, Inc. Using a snapshot as a data source
US20060136685A1 (en) * 2004-12-17 2006-06-22 Sanrad Ltd. Method and system to maintain data consistency over an internet small computer system interface (iSCSI) network
US7657578B1 (en) * 2004-12-20 2010-02-02 Symantec Operating Corporation System and method for volume replication in a storage environment employing distributed block virtualization
JP2006178811A (en) 2004-12-24 2006-07-06 Hitachi Ltd Storage system, and path control method for the system
US7398354B2 (en) * 2005-01-21 2008-07-08 International Business Machines Corporation Achieving data consistency with point-in-time copy operations in a parallel I/O environment
JP2006209636A (en) * 2005-01-31 2006-08-10 Hitachi Ltd Method for maintaining snapshot
US7928591B2 (en) * 2005-02-11 2011-04-19 Wintec Industries, Inc. Apparatus and method for predetermined component placement to a target platform
US7461221B2 (en) * 2005-03-24 2008-12-02 International Business Machines Corporation Apparatus, system, and program for automatic backup of related data
JP4728031B2 (en) * 2005-04-15 2011-07-20 株式会社日立製作所 System that performs remote copy pair migration
JP4749112B2 (en) * 2005-10-07 2011-08-17 株式会社日立製作所 Storage control system and method
US7647456B2 (en) * 2005-12-01 2010-01-12 International Business Machines Corporation Comparing data in a new copy relationship to data in preexisting copy relationships for defining how to copy data from source to target
US7653650B2 (en) * 2005-12-13 2010-01-26 International Business Machines Corporation Apparatus, system, and method for synchronizing change histories in enterprise applications
US8661216B2 (en) 2005-12-19 2014-02-25 Commvault Systems, Inc. Systems and methods for migrating components in a hierarchical storage network
US7606844B2 (en) 2005-12-19 2009-10-20 Commvault Systems, Inc. System and method for performing replication copy storage operations
US7636743B2 (en) 2005-12-19 2009-12-22 Commvault Systems, Inc. Pathname translation in a data replication system
US7617262B2 (en) 2005-12-19 2009-11-10 Commvault Systems, Inc. Systems and methods for monitoring application data in a data replication system
EP1974296B8 (en) 2005-12-19 2016-09-21 Commvault Systems, Inc. Systems and methods for performing data replication
US7962709B2 (en) 2005-12-19 2011-06-14 Commvault Systems, Inc. Network redirector systems and methods for performing data replication
US7651593B2 (en) 2005-12-19 2010-01-26 Commvault Systems, Inc. Systems and methods for performing data replication
JP4800056B2 (en) * 2006-02-09 2011-10-26 株式会社日立製作所 Storage system and control method thereof
US7509467B2 (en) * 2006-01-13 2009-03-24 Hitachi, Ltd. Storage controller and data management method
JP4903461B2 (en) * 2006-03-15 2012-03-28 株式会社日立製作所 Storage system, data migration method, and server apparatus
US7571292B2 (en) 2006-03-21 2009-08-04 International Business Machines Corporation Producing tertiary instant virtual copies without volume suspension
US7613890B1 (en) * 2006-03-31 2009-11-03 Emc Corporation Consistent replication across multiple storage devices
US8321377B2 (en) * 2006-04-17 2012-11-27 Microsoft Corporation Creating host-level application-consistent backups of virtual machines
US8261068B1 (en) 2008-09-30 2012-09-04 Emc Corporation Systems and methods for selective encryption of operating system metadata for host-based encryption of data at rest on a logical unit
US7904681B1 (en) * 2006-06-30 2011-03-08 Emc Corporation Methods and systems for migrating data with minimal disruption
US8416954B1 (en) 2008-09-30 2013-04-09 Emc Corporation Systems and methods for accessing storage or network based replicas of encrypted volumes with no additional key management
US8726242B2 (en) 2006-07-27 2014-05-13 Commvault Systems, Inc. Systems and methods for continuous data replication
US7761424B2 (en) * 2006-08-10 2010-07-20 International Business Machines Corporation Recording notations per file of changed blocks coherent with a draining agent
US20080065828A1 (en) * 2006-09-11 2008-03-13 Shigeki Iwamoto Method for storing data in electronic computer system and electronic computer system
KR100816053B1 (en) * 2006-11-21 2008-03-21 엠텍비젼 주식회사 Memory device, memory system and dual port memory device with self-copy function
EP2100224B1 (en) * 2007-01-03 2010-12-22 Raytheon Company Computer storage system
US7793148B2 (en) * 2007-01-12 2010-09-07 International Business Machines Corporation Using virtual copies in a failover and failback environment
US8290808B2 (en) 2007-03-09 2012-10-16 Commvault Systems, Inc. System and method for automating customer-validated statement of work for a data storage environment
US7644300B1 (en) * 2007-04-20 2010-01-05 3Par, Inc. Fast resynchronization of data from a remote copy
US20080294701A1 (en) * 2007-05-21 2008-11-27 Microsoft Corporation Item-set knowledge for partial replica synchronization
US8505065B2 (en) * 2007-06-20 2013-08-06 Microsoft Corporation Access control policy in a weakly-coherent distributed collection
US7685185B2 (en) * 2007-06-29 2010-03-23 Microsoft Corporation Move-in/move-out notification for partial replica synchronization
US20090006489A1 (en) * 2007-06-29 2009-01-01 Microsoft Corporation Hierarchical synchronization of replicas
US8214685B2 (en) * 2008-10-31 2012-07-03 Hewlett-Packard Development Company, L.P. Recovering from a backup copy of data in a multi-site storage system
US8204859B2 (en) 2008-12-10 2012-06-19 Commvault Systems, Inc. Systems and methods for managing replicated database data
CN101419616A (en) * 2008-12-10 2009-04-29 阿里巴巴集团控股有限公司 Data synchronization method and apparatus
US9495382B2 (en) 2008-12-10 2016-11-15 Commvault Systems, Inc. Systems and methods for performing discrete data replication
US8166314B1 (en) 2008-12-30 2012-04-24 Emc Corporation Selective I/O to logical unit when encrypted, but key is not available or when encryption status is unknown
US9092500B2 (en) 2009-09-03 2015-07-28 Commvault Systems, Inc. Utilizing snapshots for access to databases and other applications
US8719767B2 (en) 2011-03-31 2014-05-06 Commvault Systems, Inc. Utilizing snapshots to provide builds to developer computing devices
US8595191B2 (en) 2009-12-31 2013-11-26 Commvault Systems, Inc. Systems and methods for performing data management operations using snapshots
US8250122B2 (en) * 2009-11-24 2012-08-21 International Business Machines Corporation Systems and methods for simultaneous file transfer and copy actions
WO2011082132A1 (en) 2009-12-31 2011-07-07 Commvault Systems, Inc. Systems and methods for analyzing snapshots
US8504517B2 (en) 2010-03-29 2013-08-06 Commvault Systems, Inc. Systems and methods for selective data replication
US8504515B2 (en) 2010-03-30 2013-08-06 Commvault Systems, Inc. Stubbing systems and methods in a data replication environment
US8725698B2 (en) 2010-03-30 2014-05-13 Commvault Systems, Inc. Stub file prioritization in a data replication system
US8352422B2 (en) 2010-03-30 2013-01-08 Commvault Systems, Inc. Data restore systems and methods in a replication environment
US8572038B2 (en) 2010-05-28 2013-10-29 Commvault Systems, Inc. Systems and methods for performing data replication
US20120179885A1 (en) * 2010-11-17 2012-07-12 Wade Gregory L Write control system
US8799222B2 (en) * 2010-12-17 2014-08-05 Symantec Corporation Host based software block level replication using metadata indicating changed data objects at source and secondary nodes
US8577934B2 (en) * 2011-03-24 2013-11-05 Spectra Logic Corporation System and method for a storage system response with data migration
US8463746B2 (en) 2011-03-30 2013-06-11 International Business Machines Corporation Method and system for replicating data
US8751762B2 (en) 2011-03-30 2014-06-10 International Business Machines Corporation Prevention of overlay of production data by point in time copy operations in a host based asynchronous mirroring environment
JP5838652B2 (en) * 2011-08-23 2016-01-06 富士通株式会社 Data copy processing system
US9058120B2 (en) * 2011-11-09 2015-06-16 International Business Machines Corporation Setting optimal space allocation policy for creating dependent snapshots to enhance application write performance and reduce resource usage
US9372910B2 (en) * 2012-01-04 2016-06-21 International Business Machines Corporation Managing remote data replication
US9298715B2 (en) 2012-03-07 2016-03-29 Commvault Systems, Inc. Data storage system utilizing proxy device for storage operations
US9471578B2 (en) 2012-03-07 2016-10-18 Commvault Systems, Inc. Data storage system utilizing proxy device for storage operations
US9342537B2 (en) 2012-04-23 2016-05-17 Commvault Systems, Inc. Integrated snapshot interface for a data storage system
US9098466B2 (en) * 2012-10-29 2015-08-04 International Business Machines Corporation Switching between mirrored volumes
US9336226B2 (en) 2013-01-11 2016-05-10 Commvault Systems, Inc. Criteria-based data synchronization management
US9886346B2 (en) 2013-01-11 2018-02-06 Commvault Systems, Inc. Single snapshot for multiple agents
US9032172B2 (en) * 2013-02-11 2015-05-12 International Business Machines Corporation Systems, methods and computer program products for selective copying of track data through peer-to-peer remote copy
US9703701B2 (en) 2013-03-28 2017-07-11 Hewlett Packard Enterprise Development Lp Address range transfer from first node to second node
EP2979187B1 (en) 2013-03-28 2019-07-31 Hewlett-Packard Enterprise Development LP Data flush of group table
WO2015033451A1 (en) * 2013-09-06 2015-03-12 株式会社日立製作所 Distributed storage system, and data-access method therefor
US9495251B2 (en) 2014-01-24 2016-11-15 Commvault Systems, Inc. Snapshot readiness checking and reporting
US9753812B2 (en) 2014-01-24 2017-09-05 Commvault Systems, Inc. Generating mapping information for single snapshot for multiple applications
US9632874B2 (en) 2014-01-24 2017-04-25 Commvault Systems, Inc. Database application backup in single snapshot for multiple applications
US9639426B2 (en) 2014-01-24 2017-05-02 Commvault Systems, Inc. Single snapshot for multiple applications
US10339010B1 (en) * 2014-04-05 2019-07-02 Bruce Talley Systems and methods for synchronization of backup copies
US9774672B2 (en) 2014-09-03 2017-09-26 Commvault Systems, Inc. Consolidated processing of storage-array commands by a snapshot-control media agent
US10042716B2 (en) 2014-09-03 2018-08-07 Commvault Systems, Inc. Consolidated processing of storage-array commands using a forwarder media agent in conjunction with a snapshot-control media agent
US9648105B2 (en) 2014-11-14 2017-05-09 Commvault Systems, Inc. Unified snapshot storage management, using an enhanced storage manager and enhanced media agents
US9448731B2 (en) 2014-11-14 2016-09-20 Commvault Systems, Inc. Unified snapshot storage management
US10303782B1 (en) 2014-12-29 2019-05-28 Veritas Technologies Llc Method to allow multi-read access for exclusive access of virtual disks by using a virtualized copy of the disk
US10311150B2 (en) 2015-04-10 2019-06-04 Commvault Systems, Inc. Using a Unix-based file system to manage and serve clones to windows-based computing clients
US9830105B1 (en) * 2015-12-21 2017-11-28 EMC IP Holding Company LLC Migrating data objects together with their snaps
US10152527B1 (en) 2015-12-28 2018-12-11 EMC IP Holding Company LLC Increment resynchronization in hash-based replication
US10466927B2 (en) * 2016-02-17 2019-11-05 Honeywell International Inc. Replication of memory image for efficient simultaneous uses
US10503753B2 (en) 2016-03-10 2019-12-10 Commvault Systems, Inc. Snapshot replication operations based on incremental block change tracking
US10310951B1 (en) 2016-03-22 2019-06-04 EMC IP Holding Company LLC Storage system asynchronous data replication cycle trigger with empty cycle detection
US10324635B1 (en) 2016-03-22 2019-06-18 EMC IP Holding Company LLC Adaptive compression for data replication in a storage system
US10565058B1 (en) 2016-03-30 2020-02-18 EMC IP Holding Company LLC Adaptive hash-based data replication in a storage system
US9959063B1 (en) * 2016-03-30 2018-05-01 EMC IP Holding Company LLC Parallel migration of multiple consistency groups in a storage system
US10095428B1 (en) 2016-03-30 2018-10-09 EMC IP Holding Company LLC Live migration of a tree of replicas in a storage system
US9983937B1 (en) 2016-06-29 2018-05-29 EMC IP Holding Company LLC Smooth restart of storage clusters in a storage system
US10013200B1 (en) 2016-06-29 2018-07-03 EMC IP Holding Company LLC Early compression prediction in a storage system with granular block sizes
US10048874B1 (en) 2016-06-29 2018-08-14 EMC IP Holding Company LLC Flow control with a dynamic window in a storage system with latency guarantees
CN106648993B (en) * 2016-12-30 2019-07-19 杭州宏杉科技股份有限公司 The method and device of consistency group snapshot management
US10365978B1 (en) * 2017-07-28 2019-07-30 EMC IP Holding Company LLC Synchronization of snapshots in a distributed consistency group
US10740022B2 (en) 2018-02-14 2020-08-11 Commvault Systems, Inc. Block-level live browsing and private writable backup copies using an ISCSI server
US11042318B2 (en) 2019-07-29 2021-06-22 Commvault Systems, Inc. Block-level data replication
US20220263897A1 (en) * 2019-09-13 2022-08-18 Pure Storage, Inc. Replicating Multiple Storage Systems Utilizing Coordinated Snapshots
US11748329B2 (en) * 2020-01-31 2023-09-05 Salesforce, Inc. Updating a multi-tenant database concurrent with tenant cloning
US11809285B2 (en) 2022-02-09 2023-11-07 Commvault Systems, Inc. Protecting a management database of a data storage management system to meet a recovery point objective (RPO)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000049500A1 (en) * 1999-02-17 2000-08-24 Emc Corporation Method and apparatus for cascading data through redundant data storage units

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5544347A (en) * 1990-09-24 1996-08-06 Emc Corporation Data storage system controlled remote data mirroring with respectively maintained data indices
US5577222A (en) * 1992-12-17 1996-11-19 International Business Machines Corporation System for asynchronously duplexing remote data by sending DASD data grouped as a unit periodically established by checkpoint based upon the latest time value
US5771354A (en) * 1993-11-04 1998-06-23 Crawford; Christopher M. Internet online backup system provides remote storage for customers using IDs and passwords which were interactively established when signing up for backup services
US5809527A (en) * 1993-12-23 1998-09-15 Unisys Corporation Outboard file cache system
JPH086854A (en) * 1993-12-23 1996-01-12 Unisys Corp Outboard-file-cache external processing complex
US5684984A (en) * 1994-09-29 1997-11-04 Apple Computer, Inc. Synchronization and replication of object databases
US5835953A (en) * 1994-10-13 1998-11-10 Vinca Corporation Backup system that takes a snapshot of the locations in a mass storage device that has been identified for updating prior to updating
US5819310A (en) * 1996-05-24 1998-10-06 Emc Corporation Method and apparatus for reading data from mirrored logical volumes on physical disk drives
US6009481A (en) * 1996-09-30 1999-12-28 Emc Corporation Mass storage system using internal system-level mirroring
US5787415A (en) * 1996-10-30 1998-07-28 International Business Machines Corporation Low maintenance data delivery and refresh system for decision support system database
US6131148A (en) * 1998-01-26 2000-10-10 International Business Machines Corporation Snapshot copy of a secondary volume of a PPRC pair
US6253295B1 (en) * 1998-07-20 2001-06-26 International Business Machines Corporation System and method for enabling pair-pair remote copy storage volumes to mirror data in another pair of storage volumes
US6397307B2 (en) * 1999-02-23 2002-05-28 Legato Systems, Inc. Method and system for mirroring and archiving mass storage
US6446176B1 (en) * 2000-03-09 2002-09-03 Storage Technology Corporation Method and system for transferring data between primary storage and secondary storage using a bridge volume and an internal snapshot copy of the data being transferred
US6526419B1 (en) * 2000-06-09 2003-02-25 International Business Machines Corporation Method, system, and program for remote copy in an open systems environment

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000049500A1 (en) * 1999-02-17 2000-08-24 Emc Corporation Method and apparatus for cascading data through redundant data storage units

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106815091A (en) * 2015-11-27 2017-06-09 成都华为技术有限公司 Synchronous continuous transmission method, from end equipment and system
CN106815091B (en) * 2015-11-27 2020-02-14 成都华为技术有限公司 Synchronous continuous transmission method, slave end equipment and system

Also Published As

Publication number Publication date
US20020133512A1 (en) 2002-09-19
AU2002244140A1 (en) 2002-09-24
US6643671B2 (en) 2003-11-04
US20020133511A1 (en) 2002-09-19
WO2002073410A3 (en) 2003-10-16
US6728736B2 (en) 2004-04-27

Similar Documents

Publication Publication Date Title
US6728736B2 (en) System and method for synchronizing a data copy using an accumulation remote copy trio
US8209282B2 (en) Method, system, and article of manufacture for mirroring data at storage locations
US7134044B2 (en) Method, system, and program for providing a mirror copy of data
EP1639470B1 (en) Method, system and program for handling a failover to a remote storage location
US7117386B2 (en) SAR restart and going home procedures
US7660955B2 (en) Node polling in consistency group formation
US7412576B2 (en) Remote copy system having multiple data centers
US7657718B1 (en) Storage automated replication processing
US7747576B2 (en) Incremental update control for remote copy
EP2521037B1 (en) Geographically distributed clusters
US7225307B2 (en) Apparatus, system, and method for synchronizing an asynchronous mirror volume using a synchronous mirror volume
US7251743B2 (en) Method, system, and program for transmitting input/output requests from a primary controller to a secondary controller
US5446871A (en) Method and arrangement for multi-system remote data duplexing and recovery
US10191755B1 (en) Virtual replication
US7111004B2 (en) Method, system, and program for mirroring data between sites
US8862541B1 (en) N-site asynchronous replication
US7831550B1 (en) Propagating results of a volume-changing operation to replicated nodes
JP2007052772A (en) Data replication system and data migration method
JP2005276162A (en) Distributed remote copy system
US7069400B2 (en) Data processing system
WO2008085483A2 (en) Toggling between concurrent and cascaded triangular asynchronous replication

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP