JP2009020914A - Storage controller, storage control program, storage control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage controller, a storage control program, and a storage control method, capable of storing a backup for each generation of storage at low cost. <P>SOLUTION: The storage controller for creating the generation backup of the prescribed storage is provided with the first copying part for creating at least any snap shot of all the data of the prescribed storage at an indicated time point and a differential data of the prescribed storage in an indicated period, the second copying part for creating at least any mirror of all the data of the prescribed storage and the differential data of the prescribed storage in the indicated period, and a control part for making one of the first and second copying parts execute the copy of all the data of the prescribed storage, and for making the other execute the copy of the differential data of the prescribed storage between the generations. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a storage control device, a storage control program, and a storage control method for collecting storage backups for each generation.

  Usually, in a computer system, a backup is collected for data recovery from a failure or an operation error. There are OPC (One Point Copy) and EC (Equivalent Copy) as expanded copy functions used for collecting backups. The OPC mainly creates a snapshot, and the copy destination storage data is the copy source storage data at the time of the instruction. The EC mainly creates a mirror, and the data in the copy destination storage is synchronized with the data in the copy source storage in the designated period.

As a related art related to the present invention, a snapshot image including a data holding unit for storing a snapshot image at a certain point in time and another data holding unit for storing subsequent update data, an update area, and a generation is provided. There is a generation management method (see, for example, Patent Document 1).
JP 2005-292865 A

  When considering recovery from backup data, it is desirable to collect multiple generations of backups at fine time intervals. However, in the conventional technique, when collecting multiple generations of backups, it is necessary to prepare volumes having the same capacity as the backup source for the number of generations. Further, in the technique such as Patent Document 1, it is necessary to newly prepare a mirroring function and a path configuration for simultaneously writing to the current generation storage and the backup storage in advance. In addition, when time elapses from the first copy, the number of update data increases and the load of restore processing increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a storage control device, a storage control program, and a storage control method that collect backups for each generation of storage at low cost.

  In order to solve the above-described problem, an aspect of the present invention is a storage control apparatus that creates a generational backup of a predetermined storage for storing data, and stores data in a predetermined storage up to a designated first time point. A first copy unit for copying to the pre-update data storage, a second copy unit for copying updated data in the predetermined storage to the post-update data storage in a predetermined period after the first time point, and a target time for restoration When a restore instruction is received, the controller has a controller that restores the data at the designated second time point using the data in the pre-update data storage and the data in the post-update data storage before the target time.

  According to another aspect of the present invention, there is provided a storage control program for causing a computer to create a generational backup of a predetermined storage for storing data. The computer stores data in a predetermined storage up to a designated first time point. A first copy unit for copying to the pre-update data storage, a second copy unit for copying updated data in the predetermined storage to the post-update data storage in a predetermined period after the first time point, and a target time for restoration A storage control comprising: a control unit that restores data at a specified second time point using a data in the pre-update data storage and data in the post-update data storage before the target time when a restore instruction is received To function as a device.

  Another embodiment of the present invention is a storage control method for causing a computer to create a generational backup of a predetermined storage for storing data, wherein the data in the predetermined storage up to the instructed first time point is pre-update data. Copy to the storage for storage, copy the updated data of the predetermined storage in the predetermined period after the first time point to the updated data storage, and receive a restore instruction including the target time of the restore, Using the data and the data in the updated data storage before the target time, the computer is caused to restore the data at the designated second time point.

  According to the present invention, backup for each generation of storage can be collected at low cost.

  Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG.
In the present embodiment, a storage control apparatus that performs generation backup processing and generation restore processing using OPC (processing by the first copy unit) and differential EC (processing by the second copy unit) will be described. OPC is used to collect backups of all user disks of the first generation, and differential EC that copies only the difference from the previous generation is used by EC to collect backups of subsequent generations.

  First, the configuration of a storage apparatus using the storage control apparatus according to this embodiment will be described.

  FIG. 1 is a block diagram illustrating an example of a configuration of a storage apparatus according to the first embodiment. This storage device 1 is connected to a host 2. The storage device 1 includes a CA (Channel Adapter) 11, a CM (Centralized Module) 12 (storage control device), and a disk 13. The CM 12 includes a CPU (Central Processing Unit) 21 (first copy unit, second copy unit, control unit), cache memory (Cache) 22, and FC (Fibre Channel) control unit (FC) 23.

  The host 2 accepts operator operations and accesses the storage apparatus 1. The CA 11 controls the interface with the host 2. The FC control unit 23 controls the interface with the disk 13. The cache memory 22 stores user data and control data. The CPU 21 performs resource management and copy control for the cache memory 22, the FC control unit 23, and the CA 11.

  The disk 13 according to the present embodiment includes a user disk that is a copy source, an OPC disk that is a copy destination of a copy of the entire user disk by OPC, a differential EC disk A that is a copy destination of differential copy by EC, and a differential EC disk B , Composed of a differential EC disk C.

  Next, control data according to the present embodiment will be described.

  The cache memory 22 stores, as control data, copy session management information, an LBA (Logical Block Address) conversion table, and a generation management table.

  First, copy session management information will be described. FIG. 2 is a table showing an example of the structure of the copy session management information according to the first embodiment. A unit of copy processing such as one OPC or one differential EC is called a session, and is called an OPC session, differential EC session A, or the like. The copy session management information includes session identifier, session type, session status, copy target range (copy source LUN (Logical Unit Number), copy destination LUN, copy source copy target start LBA, copy destination copy target start LBA, number of copy target LBAs. ), And a BitMap indicating an uncopied area. The session identifier is a unique number indicating the session. The session type has values such as OPC, EC, differential OPC, and differential EC. The session status represents the state of the session, and has values such as “Active” and “Suspended”.

  Next, the LBA conversion table will be described. FIG. 3 is a table showing an example of the structure of the LBA conversion table according to the first embodiment. This LBA conversion table holds information indicating the data storage position on the differential EC disk. Here, the logical LBA indicating the LBA on the user disk is associated with the physical LBA actually stored on the differential EC disk.

  Next, the generation management table will be described. FIG. 4 is a table showing an example of the structure of the generation management table according to the first embodiment. This generation management table manages generations between sessions, and includes a generation number, a collection time (time when a session is set), and a session identifier. As for the session identifier, only the first generation is the identifier of the OPC session, and the subsequent generation is the identifier of the differential EC session.

  Next, generation backup processing according to the present embodiment will be described.

  The generation backup processing includes generation backup start processing, generation switching processing, generation backup write I / O processing, and differential EC management processing. Here, the OPC session is to create a snapshot of all data on the user disk at the start of the OPC session on the OPC disk. Further, the differential EC session creates a mirror of the difference data of the user disk from the start of the differential EC session on the corresponding differential EC disk from the start of the differential EC session to the temporary suspension of the differential EC session.

  First, generation backup start processing will be described. FIG. 5 is a flowchart showing an example of operation of generation backup start processing according to the first embodiment. First, when receiving an instruction for generation backup processing via the host 2 or LAN (S111), the CPU 21 performs settings for starting an OPC session and starting a differential EC session A (S112). Next, the OPC session by the CPU 21 starts backup of the entire user disk (Initial copy process) (S113). Next, the differential EC session A by the CPU 21 waits until a write I / O is issued (S114), and this flow ends.

  Next, generation switching processing will be described. Here, a case where the differential EC session A is in operation and is switched to the differential EC session B will be described. FIG. 6 is a flowchart showing an example of the operation of the generation switching process according to the first embodiment. First, when receiving an instruction to switch generations via the host 2 or the LAN (S151), the CPU 21 performs settings for differential EC session A temporary stop and differential EC session B start (S152). Next, the differential EC session A by the CPU 21 holds the state until a restore instruction for recovery is given (S153), and the differential EC session B by the CPU 21 waits until a write I / O is issued (S154). This flow ends.

  Next, Write I / O processing during generation backup will be described. FIG. 7 is a flowchart showing an example of operation of the generation I / O processing during generation backup according to the first embodiment. First, when the CPU 21 receives a write I / O instruction for the user disk via the host 2 or the LAN (S211), the CPU 21 determines whether backup to the OPC disk has been completed within the I / O range (S212). . If it has been completed (S212, Yes), the process proceeds to S214. On the other hand, if it has not been completed (S212, No), the CPU 21 copies the pre-update data to the OPC disk (S213). Next, the CPU 21 executes Write I / O (S214). Next, the CPU 21 confirms the currently operating differential EC session (S215), copies the update data to the confirmed operational differential EC disk (S216), and this flow ends.

  Next, the differential EC management process will be described.

  The differential EC management process is a process for managing a differential EC session. The CPU 21 stores a correspondence relationship between position information (logical LBA) on the user disk and physical position information (physical LBA) stored on the differential EC disk as an LBA conversion table and uses it for control. In addition, when an update is performed on the user disk that is the copy source during the differential EC session, the CPU 21 stores the update data in the left-justified space in the differential EC disk that is the copy destination.

  Here, an operation when Read I / O or Write I / O is issued from the host 2 during the differential EC session will be described.

  When a write I / O is issued to the copy source, the CPU 21 stores the update data in the copy destination. At this time, the CPU 21 stores the update data in a free area on the copy destination physical disk.

  When a write I / O is issued to the copy destination, the CPU 21 checks whether the corresponding data already exists on the copy destination physical disk. When it exists, CPU21 reflects update data with respect to the area | region. On the other hand, if it does not exist, the CPU 21 stores the update data in a free area on the copy destination physical disk.

  When data a is requested when Read I / O is issued to the copy destination, the data b corresponding to the data a is searched on the physical disk of the copy destination generation n. When the data b exists, the CPU 21 transfers the data b existing on the physical disk. When the data b does not exist, the data corresponding to the data a is searched on the physical disk of the generation (n−m) (m = 1, 2, 3...). When the corresponding data b exists, the CPU 21 transfers the data b. If there is no corresponding data even after searching all generations of physical disks, the CPU 21 transfers the data on the OPC disk.

  Next, a specific example of the above-described generation backup process will be described.

  FIG. 8 is a diagram illustrating an example of a specific operation of the generation backup process according to the first embodiment. First, it is assumed that the storage control device 1 receives a generation backup processing instruction from the host 2 at time TA. At this time, the CPU 21 starts the OPC session and the differential EC session A by executing generation backup start processing. The OPC session starts backup from the user disk to the OPC disk. The differential EC session A waits unless Write I / O is performed.

  Next, it is assumed that the storage control device 1 receives Write I / O (WT (a)) from the host 2 at time TB. At this time, if there is data that is not copied from the user disk to the OPC disk in the I / O range, the OPC session copies the pre-update data (WT (a) old) to the OPC disk. The difference EC session A copies the update data (WT (a)) of the user disk to the difference EC disk A.

  Next, it is assumed that the storage control device 1 receives a generation switching processing instruction from the host 2 at time TC. At this time, the CPU 21 temporarily stops the differential EC session A and starts a differential EC session B that simultaneously records the next generation differential data. Thereafter, the differential EC session B copies the update data of the user disk to the differential EC disk B.

  Next, it is assumed that the storage control device 1 receives Write I / O (WT (b)) from the host 2 at time TD. At this time, if there is data that has not been copied from the user disk to the OPC disk in the I / O range, the OPC session copies the pre-update data (WT (b) old) to the OPC disk. The differential EC session B copies the update data (WT (b)) of the user disk to the differential EC disk B.

  Next, it is assumed that the storage control device 1 receives a generation switching processing instruction from the host 2 at time TE. At this time, the CPU 21 temporarily stops the differential EC session B, and simultaneously starts the differential EC session C for recording the next generation differential data. Thereafter, the differential EC session C copies the update data of the user disk to the differential EC disk C.

  Next, it is assumed that the storage control device 1 receives Write I / O (WT (c)) from the host 2 at time TF. At this time, if there is data that has not been copied from the user disk to the OPC disk in the I / O range, the OPC session copies the pre-update data (WT (c) old) to the OPC disk. The differential EC session C copies the update data (WT (c)) of the user disk to the differential EC disk C.

  Thereafter, the generation switching process is performed at the time when the backup is desired to be collected.

  According to the above-described generation backup processing, only the data that has been updated is stored in the differential EC disk, and when the update amount is small, the disk capacity can be made smaller than that of the user disk. In addition, by implementing using OPC and differential EC, it is possible to collect a backup for each generation without stopping access from the host 2.

  Next, generation restore processing according to the first embodiment will be described.

  The generation restore process is a process for restoring a user disk from backup data of a specified generation among backup data saved on an OPC disk and a differential EC disk when a failure occurs. The generation restore process includes a restore start process and a generation restore I / O process.

  Next, restore start processing according to the present embodiment will be described. FIG. 9 is a flowchart showing an example of the operation of the restore start process according to the first embodiment. First, when the CPU 21 receives a generation restore processing instruction including a restore specified time via the host 2 or the LAN (S311), whether or not there is data that has not yet been restored on the differential EC disk before the restore specified time. Is determined (S312). Here, the restore designated time is a time that indicates when the user disk is to be restored by the restore. When there is data that has not been restored (S312: Yes), the CPU 21 reflects the corresponding data on the differential EC disk in order from the oldest to the OPC disk (merge processing) (S313), and processing S312. Return to. On the other hand, if there is no data that has not been restored (No at S312), the CPU 21 restores from the OPC disk to the user disk (S314), and this flow ends.

  Next, I / O processing during generation restoration according to this embodiment will be described. FIG. 10 is a flowchart showing an example of the operation of the I / O processing during generation restoration according to the first embodiment. First, when the CPU 21 receives Read I / O or Write I / O for a user disk that is undergoing generation restore processing (S351), the CPU 21 determines whether or not restoration to the user disk has been completed within the I / O range ( S352).

  If it has been completed (S352, Yes), the process proceeds to S356. On the other hand, if it has not been completed (S352, No), the CPU 21 determines whether there is data that has not yet been restored on the differential EC disk before the restore designated time in the I / O range (S353). ). If there is data that has not been restored (S353, Yes), the CPU 21 searches the I / O range for the latest data in a time series from a plurality of generations of differential EC disks before the restore designated time, and the data. Is restored to the user disk (S354), and the process proceeds to S356. On the other hand, if there is no data that has not been restored (S353, No), the CPU 21 restores the data of the OPC disk to the user disk (S355), and proceeds to the process S356. Next, the generation restoration process is completed (S356), the designated Read I / O or Write I / O is executed (S357), and this flow ends.

  Next, a specific example of the above-described generation restoration process will be described.

  FIG. 11 is a diagram illustrating an example of a specific operation of the generation restoration process according to the first embodiment. Here, the OPC session and the differential EC session A are started by the generation backup start process at 9:00, and the differential EC session A is switched to the differential EC session B by the generation switching process at 10:00 (to the differential EC disk A). The copy is completed), and the difference EC session B is switched from the differential EC session B to the differential EC session C by the generation switching process at 11:00 (the copy to the differential EC disk B is completed), and then the restore designation time is set to 11:00. A case where the above is performed will be described.

  First, the restoration start process will be described. The CPU 21 updates the update data (WT (a)) from the OPC disk (WT (a) old, WT (b) old, WT (c) old) and the differential EC disk A created at 10:00 to the differential EC disk A. ) Exists (S312). If it exists, the corresponding data is merged into the OPC disk (S313). Next, the CPU 21 checks whether update data (WT (b)) exists in the differential EC disk B created at 11:00 (S312). If it exists, the CPU 21 further merges the corresponding data into the OPC disk (S313). Next, the CPU 21 restores from the OPC disk (WT (a), WT (b), WT (c) old) to the user disk (S314).

  Next, I / O processing during generation restoration will be described. First, the CPU 21 checks whether or not the corresponding I / O range has been restored (S352), and if restored, executes the I / O as it is (S357). If the restoration has not been performed yet, the CPU 21 checks whether update data exists in the differential EC disk B corresponding to the restore designated time 11:00 (S353). If update data exists on the differential EC disk B, the update data on the differential EC disk B is restored to the user disk (S354), and I / O is executed (S357). If there is no update data in the differential EC disk B, it is checked whether there is update data in the differential EC disk A that is one generation before the checked differential EC disk B (S353). When update data exists on the differential EC disk A, the update data on the differential EC disk A is restored to the user disk (S354), and I / O is executed (S357). If there is no update data on the differential EC disk A, it is confirmed that there is no differential EC disk before the checked differential EC disk A, and the data of the OPC disk is restored to the user disk (S355). / O is executed (S357).

  According to the above-described generation restore processing, when generation restore processing is performed while the user disk is online, generation restore I / O processing is performed in response to I / O issuance during generation restore processing. This process makes it possible to execute the generation restore process without stopping the I / O from the user. From the user's point of view, it seems that the generation restore processing is completed when the restore instruction is issued.

  Next, tape backup processing will be described.

  The tape backup process is to copy the data of the OPC disk obtained by the above-described generation backup process, the data of a plurality of generations of differential EC disks, and the LBA conversion table to the tape. Among these, the data of the differential EC disk and the LBA conversion table cannot be directly referred to from the host 2, so a special command used by the host 2 is prepared. The special commands are Read of data from the differential EC disk, Write of data to the differential EC disk, Read of the LBA conversion table of the differential EC disk, and Write of the LBA conversion table of the differential EC disk.

  FIG. 12 is a flowchart showing an example of the operation of the tape backup process according to the first embodiment. First, the CPU 21 backs up the data of the OPC disk to a tape according to the normal Read command from the host 2 (S411). Next, the CPU 21 backs up the data of the differential EC disk to a tape according to the special command from the host 2 (S412). Next, the CPU 21 backs up the LBA conversion table to the tape according to the special command from the host 2 (S413), and this flow ends.

  According to the tape backup process described above, the backup of the differential EC disk is reduced in size and processing time as compared with the backup of all the data for each generation to the tape, which has conventionally required enormous time. be able to.

Embodiment 2. FIG.
In this embodiment, a storage control apparatus that performs generation backup processing and generation restore processing using EC (processing by the second copy unit) and differential OPC (processing by the first copy unit) will be described. In other words, during generation backup processing, EC copying is performed, and differential OPC is used to copy only the difference from the previous generation by OPC when collecting backups for each generation.

  First, the configuration of a storage apparatus using the storage control apparatus according to this embodiment will be described.

  The configuration of the storage apparatus according to this embodiment is the same as that of the first embodiment. The disk 13 according to the present embodiment includes a user disk that is a copy source, an EC disk that is a copy destination of a copy of the entire user disk by EC, a differential OPC disk A that is a copy destination of differential copy by OPC, and a differential OPC disk B , The differential OPC disk C.

  Next, control data according to the present embodiment will be described.

  The control data is copy session management information, an LBA conversion table, and a generation management table, as in the first embodiment. The copy session management information is the same as in the first embodiment. The LBA conversion table holds information indicating the data storage position on the differential OPC disk. Here, the logical LBA indicating the LBA on the user disk is associated with the physical LBA actually stored on the differential OPC disk.

  Next, the generation management table will be described. FIG. 13 is a table showing an example of the structure of the generation management table according to the second embodiment. The structure of this generation management table is the same as that of the first embodiment, but the session identifier is the EC session identifier only for the first generation, and the subsequent generation is the identifier of the differential OPC session.

  Next, generation backup processing according to the present embodiment will be described.

  The generation backup processing includes generation backup start processing, generation switching processing, generation backup Write I / O processing, differential OPC management processing, and differential OPC deletion processing, as in the first embodiment. Here, the EC session is a copy to synchronize the EC disk with the user disk during the EC session. The differential OPC session is a copy of the user disk data difference from the start of the differential OPC session to the stop of the differential OPC session to the corresponding differential OPC disk.

  First, generation backup start processing will be described. FIG. 14 is a flowchart illustrating an example of operation of generation backup start processing according to the second embodiment. First, when receiving an instruction for generation backup processing via the host 2 or LAN (S511), the CPU 21 sets EC session start and differential OPC session A start (S512). Next, the EC session by the CPU 21 starts mirroring processing of the entire user disk (Initial copy processing) (S513). Next, the differential OPC session A by the CPU 21 waits until a write I / O is issued (S514), and this flow ends.

  Next, generation switching processing will be described. Here, a case where the differential EC session A is in operation and is switched to the differential EC session B will be described. FIG. 15 is a flowchart illustrating an example of the operation of the generation switching process according to the second embodiment. First, when receiving an instruction to switch generations via the host 2 or the LAN (S551), the CPU 21 performs settings for temporarily stopping the differential OPC session A and starting the differential OPC session B (S552). Next, the differential OPC session A by the CPU 21 holds the state until an instruction for restoration for recovery is given (S553), and the differential OPC session B by the CPU 21 waits until a write I / O is issued (S554). This flow ends.

  Next, Write I / O processing during generation backup will be described. FIG. 16 is a flowchart showing an example of the operation of the generation I / O processing during generation backup according to the second embodiment. First, when the CPU 21 receives a write I / O instruction for the user disk via the host 2 or the LAN (S611), the CPU 21 determines whether or not the backup to the differential OPC disk currently operating in the I / O range has been completed. (S612). If it has been completed (S612, Yes), the process proceeds to S614. On the other hand, if not completed (S612, No), the CPU 21 copies the pre-update data to the operating differential OPC disk (S613). Next, the CPU 21 executes Write I / O (S614). Next, the CPU 21 copies the update data to the EC disk (S616), and this flow ends.

  Next, the differential OPC management process will be described.

  The differential OPC management process is a process for managing a differential OPC session. The CPU 21 stores a correspondence relationship between the position information (logical LBA) on the user disk and the physical position information (physical LBA) stored on the differential OPC disk as an LBA conversion table and uses it for control. In addition, when an update is performed on the user disk that is the copy source during the differential OPC session, the CPU 21 stores the update data in a free space in the differential OPC disk that is the copy destination.

  Here, an operation when Read I / O or Write I / O is issued from the host 2 during the differential OPC session will be described.

  When a write I / O is issued to the copy source, the CPU 21 stores the pre-update data in a free area on the copy destination physical disk.

  When a write I / O is issued to the copy destination, the CPU 21 stores the pre-update data in an empty area on the copy destination physical disk.

  When data a is requested when Read I / O is issued to the copy destination, the data b corresponding to the data a is searched on the physical disk of the copy destination generation n. When the data b exists, the CPU 21 transfers the data b existing on the physical disk. When the data b does not exist, the CPU 21 transfers the data on the user disk.

  Next, the differential OPC management process will be described.

  The CPU 21 deletes the generational differential OPC disk that is no longer needed. Further, the CPU 21 can delete a certain generation of differential OPC disks and use the disk as a next generation OPC disk. Therefore, generation management can be performed with a small number of disks.

  Next, a specific example of the above-described generation backup process will be described.

  FIG. 17 is a diagram illustrating an example of a specific operation of the generation backup process according to the second embodiment. First, it is assumed that the storage control device 1 receives a generation backup processing instruction from the host 2 at time TA. At this time, the CPU 21 starts the EC session and the differential OPC session A by executing generation backup start processing. The EC session starts mirroring (synchronization) from the user disk to the EC disk. The differential OPC session A waits unless Write I / O is performed.

  Next, it is assumed that the storage control device 1 receives Write I / O (WT (a)) from the host 2 at time TB. At this time, the EC session performs mirroring (WT (a)) from the user disk to the EC disk. In the differential OPC session A, if there is data that has not been copied from the user disk to the differential OPC disk A in the I / O range, the pre-update data (WT (a) old) is copied to the differential OPC disk A. .

  Next, it is assumed that the storage control device 1 receives a generation switching processing instruction from the host 2 at time TC. At this time, the CPU 21 temporarily stops the differential OPC session A, and starts a differential OPC session B that records the next generation of differential data at the same time. Thereafter, the differential OPC session B copies the update data of the user disk to the differential OPC disk B.

  Next, it is assumed that the storage control device 1 receives Write I / O (WT (b)) from the host 2 at time TD. At this time, the EC session performs mirroring (WT (b)) from the user disk to the EC disk. In the differential OPC session B, if there is data that has not been copied from the user disk to the differential OPC disk B in the I / O range, the pre-update data (WT (b) old) is copied to the differential OPC disk B. .

  Next, it is assumed that the storage control device 1 receives a generation switching processing instruction from the host 2 at time TE. At this time, the CPU 21 temporarily suspends the differential OPC session B and starts a differential OPC session C for recording the next generation differential data at the same time. Thereafter, the differential OPC session C copies the update data of the user disk to the differential OPC disk C.

  Next, it is assumed that the storage control device 1 receives Write I / O (WT (c)) from the host 2 at time TF. At this time, the EC session performs mirroring (WT (c)) from the user disk to the EC disk. In the differential OPC session C, if there is data that has not been copied from the user disk to the differential OPC disk C in the I / O range, the pre-update data (WT (c) old) is copied to the differential OPC disk C. .

  Thereafter, the generation switching process is performed at the time when the backup is desired to be collected.

  According to the above-described generation backup process, only the data that has been updated is stored in the differential OPC disk, and when the update amount is small, the disk capacity can be made smaller than that of the user disk. Further, by implementing using EC and differential OPC, it is possible to collect a backup for each generation without stopping access from the host 2.

  Next, generation restore processing according to the present embodiment will be described.

  The generation restore process is a process for restoring a user disk from backup data of a specified generation among backup data saved on an EC disk and a differential OPC disk when a failure occurs. The generation restore process includes a restore start process and a generation restore I / O process, as in the first embodiment.

  Next, restore start processing according to the present embodiment will be described. FIG. 18 is a flowchart showing an example of the operation of the restore start process according to the second embodiment. First, when the CPU 21 receives an instruction for generation restore processing including a restore specified time via the host 2 or LAN (S711), whether or not there is data that has not yet been restored in the differential OPC disk before the restore specified time. Is determined (S712). Here, the restore designated time is a time that indicates when the user disk is to be restored by the restore. If there is data that has not been restored (S712, Yes), the CPU 21 reflects the relevant data on the differential OPC disk to the user disk in chronological order (merging processing) (S713), and processing S712. Return to. On the other hand, if there is no data that has not been restored (S712, No), this flow ends.

  Next, I / O processing during generation restoration according to this embodiment will be described. FIG. 19 is a flowchart showing an example of operation of the I / O processing during generation restoration according to the second embodiment. First, when receiving Read I / O or Write I / O for a user disk that is undergoing generation restore processing (S751), the CPU 21 determines whether or not restoration to the user disk has been completed within the I / O range ( S752).

  If it has been completed (S752, Yes), the process proceeds to S756. On the other hand, if it has not been completed (S752, No), the CPU 21 determines whether there is data that has not yet been restored in the differential OPC disk before the restore designated time in the I / O range (S753). ). When there is data that has not been restored (S753, Yes), the CPU 21 searches the I / O range for the oldest data in time series among the multiple generation differential OPC disks before the restore designated time, and the data. Is restored to the user disk (S754), and the process proceeds to S756. On the other hand, if there is no data that has not been restored (S753, No), the process proceeds to S756. Next, the generation restoration process is completed (S756), the designated Read I / O or Write I / O is executed (S757), and this flow ends.

  Next, a specific example of the above-described generation restoration process will be described.

  FIG. 20 is a diagram illustrating an example of a specific operation of the generation restoration process according to the second embodiment. Here, the EC session and the differential OPC session A are started by the generation backup start process at 9:00, and the differential OPC session A is switched to the differential OPC session B by the generation switching process at 10:00 (to the differential OPC disk B). The copy is started), and the difference OPC session B is switched from the differential OPC session C to the differential OPC session C by the generation switching process at 11:00 (copying to the differential OPC disk C is started), and then the restore designation time is set to 11:00. A case where the above is performed will be described.

  First, the restoration start process will be described. The CPU 21 transfers backup data (WT (WT (a), WT (b), WT (c)) from the differential OPC disk C whose copy is started at the designated restore time 11:00 to the differential OPC disk C. c) It is checked whether old) exists (S712). If it exists, the corresponding data is merged with the user disk (S713). Next, the CPU 21 checks whether or not backup data (WT (b) old) exists in the differential OPC disk B whose copy is started at 10:00 (S712). If it exists, the CPU 21 further merges the corresponding data into the user disk (S713).

  Next, I / O processing during generation restoration will be described. First, the CPU 21 checks whether or not the corresponding I / O range has been restored (S752), and if restored, executes the I / O as it is (S757). If the restoration has not been performed yet, the CPU 21 checks whether backup data exists in the differential OPC disk C corresponding to the restore designated time 10:00 (S753). If backup data exists, the backup data on the differential OPC disk C is restored to the user disk (S754), and I / O is executed (S757). If backup data does not exist, it is checked whether backup data exists in the differential OPC disk B that is one generation before the checked differential OPC disk C (S753). If backup data exists, the backup data on the differential OPC disk B is restored to the user disk (S754), and I / O is executed (S757). If backup data does not exist, it is confirmed that the restoration up to the designated restore time is completed, and I / O is executed for the user disk (S757).

  According to the above-described generation restore processing, when generation restore processing is performed while the user disk is online, generation restore I / O processing is performed in response to I / O issuance during generation restore processing. This process makes it possible to execute the generation restore process without stopping the I / O from the user. From the user's point of view, it seems that the generation restore processing is completed when the restore instruction is issued.

  Next, tape backup processing will be described.

  The tape backup process is the same as that of the first embodiment, but copies EC disk data, multiple generation differential OPC disk data, and LBA conversion table obtained by the above-described generation backup process to a tape. The special commands are Read of data from the differential OPC disk, Write of data to the differential OPC disk, Read of the LBA conversion table of the differential OPC disk, and Write of the LBA conversion table of the differential OPC disk.

  FIG. 21 is a flowchart showing an example of the operation of the tape backup processing according to the second embodiment. First, the CPU 21 backs up the data on the EC disk to a tape according to the normal Read command from the host 2 (S811). Next, the CPU 21 backs up the data of the differential OPC disk to a tape according to a special command from the host 2 (S812). Next, the CPU 21 backs up the LBA conversion table to a tape according to the special command from the host 2 (S813), and this flow ends.

  According to the tape backup process described above, the backup of the differential OPC disk is reduced in size and processing time compared to the backup of all the data for each generation to the tape, which has conventionally required enormous time. be able to.

Embodiment 3 FIG.
In the present embodiment, a storage control apparatus that performs generation backup processing and generation restore processing using both the first embodiment and the second embodiment will be described.

  First, the configuration and control data of the storage apparatus using the storage control apparatus according to the present embodiment are the same as those in the first and second embodiments. The storage control apparatus according to the present embodiment simultaneously performs the generation backup process of the first embodiment and the generation backup process of the second embodiment.

  Next, generation restore processing according to the present embodiment will be described.

  First, when receiving an instruction for generation restore processing including a restore designated time, the CPU 21 compares the difference between the restore designated time and the generation backup processing start time, and the difference between the current time and the restore designated time. That is, the CPU 21 determines whether the specified restore time is closer to the generation backup processing start time or the current time. When the specified restore time is close to the generation backup processing start time (when it is older than the predetermined time), the CPU 21 performs the generation restore processing according to the first embodiment. On the other hand, when the restore designated time is close to the current time (when newer than the predetermined time), the CPU 21 performs the generation restore process of the second embodiment.

  Next, a specific example of the generation restoration process according to the present embodiment will be described.

  FIG. 22 is a diagram illustrating an example of a specific operation of the generation restoration process according to the third embodiment. Here, at 9:00, the OPC session and the differential EC session A are started by the generation backup start process of the first embodiment, and the EC session and the differential OPC session A are started by the generation backup start process of the second embodiment. Is started. Next, at 10:00, the differential EC session A is switched to the differential EC session B by the generation switching process of the first embodiment, and the differential OPC session A is switched to the differential OPC session B by the generation switching process of the second embodiment. Suppose that it is switched. Next, at 11:00, the differential EC session B is switched to the differential EC session C by the generation switching process of the first embodiment, and the differential OPC session B is switched to the differential OPC session C by the generation switching process of the second embodiment. Suppose that it is switched.

  If the restore specified time is 10:00 in the generation restore processing instruction at the current time 12:00, the CPU 21 determines that the restore specified time is closer to the generation backup processing start time, and the generation of the first embodiment Perform restore processing. In the instruction of the generation restore process at the current time 12:00, when the restore designated time is 11:00, the CPU 21 determines that the restore designated time is closer to the current time, and performs the generation restore process of the second embodiment. Do.

  According to the above-described generation restore process, it is possible to select one of the two generation restore processes, which has less process, and to shorten the generation restore process time.

  The first copy step corresponds to at least one of the OPC session and the EC session in the embodiment. The second copy step corresponds to at least one of the differential EC session and the differential OPC session in the embodiment. The restore step corresponds to the generation restore process in the embodiment.

  Further, the storage control device according to the present embodiment can be easily applied to the storage device, and the performance of the storage device can be further improved. Here, the storage device may include, for example, a disk device, a disk array device, or the like.

  Furthermore, a program that causes a computer constituting the storage control apparatus to execute the above steps can be provided as a storage control program. The above-described program can be executed by a computer constituting the storage control apparatus by storing the program in a computer-readable recording medium. Here, examples of the recording medium readable by the computer include an internal storage device such as a ROM and a RAM, a portable storage such as a CD-ROM, a flexible disk, a DVD disk, a magneto-optical disk, and an IC card. It includes a medium, a database holding a computer program, another computer and its database, and a transmission medium on a line.

(Supplementary note 1) A storage control device for creating a generation backup of a predetermined storage,
A first copy unit that creates a snapshot of at least one of the entire data of the predetermined storage at the specified time and the difference data of the predetermined storage during the specified period;
A second copy unit that creates a mirror of at least one of all data of the predetermined storage and difference data of the predetermined storage in a designated period;
A control unit that causes one of the first copy unit and the second copy unit to copy all data of the predetermined storage, and causes the other to copy data of the difference of the predetermined storage between generations; A storage control device.
(Supplementary note 2) In the storage control device according to supplementary note 1,
The control unit causes the first copy unit to create a snapshot of all data in the predetermined storage in the first generation, and to create a mirror of the difference data in the predetermined storage between generations in the second copy A storage control apparatus that is executed by a storage unit.
(Supplementary note 3) In the storage control device according to supplementary note 1,
The control unit causes the second copy unit to create a mirror of all data in the predetermined storage, and causes the first copy unit to create a snapshot of difference data of the predetermined storage between generations. A storage control device.
(Supplementary Note 4) In the storage control device according to Supplementary Note 1,
The control unit causes the first copy unit to create a snapshot of all data in the predetermined storage in the first generation, and causes the second copy unit to create a mirror of all data in the predetermined storage. Causing the second copy unit to create a mirror of the difference data of the predetermined storage between generations, and to create a snapshot of the difference data of the predetermined storage between generations to the first copy unit. A storage control device that is executed.
(Supplementary Note 5) In the storage control device described in Supplementary Note 2,
When a snapshot of all the data is created by the first copy unit and at least one mirror of the difference data is created by the second copy unit, a restore instruction including a restore target time is received. The control unit reflects a mirror of the difference data before the target time in the chronological order of the snapshot of all data, and reflects the snapshot of the all data after the reflection to the predetermined storage. Storage controller.
(Supplementary note 6) In the storage control device according to supplementary note 3,
After the mirror of all the data is created by the second copy unit and at least one snapshot of the differential data is created by the first copy unit, a restore instruction including a restore target time is received. The control unit reflects a snapshot of the difference data after the target time to the predetermined storage in order of newest.
(Supplementary note 7) In the storage control device according to supplementary note 4,
The first copy unit creates a snapshot of all the data, the second copy unit creates a mirror of all the data, and the second copy unit creates at least one mirror of the difference data. In addition, after the first copy unit has created at least one snapshot of the difference data and receives a restore instruction including a restore target time, the control unit receives the time of the first generation and the current time It is determined which time is closer to the target time, and when the time of the first generation is closer to the target time, the mirror of the difference data before the target time is changed to a snapshot of all the data in chronological order. Reflect, reflect the snapshot of all the data after the reflection to the predetermined storage, and the current time is earlier. If close to the target time, the storage control apparatus characterized by reflecting a snapshot of the differential data after the target time to the new order to the predetermined storage.
(Supplementary Note 8) In the storage control device according to Supplementary Note 5 or Supplementary Note 7,
When receiving an instruction to read or write the predetermined storage from the outside, the control unit is not reflected in the predetermined storage from the mirror of the difference data before the target time in the target range of the reading or writing When there is data, the storage control device characterized by reflecting the newest data in the mirror to the predetermined storage and executing the reading or writing.
(Supplementary Note 9) In the storage control device according to Supplementary Note 6 or Supplementary Note 7,
When receiving an instruction for reading or writing to the predetermined storage from the outside, the control unit reflects the snapshot of the differential data after the target time in the target range of the reading or writing to the predetermined storage. When there is no data, the storage control device is characterized in that the oldest data in the snapshot is reflected in the predetermined storage and the reading or writing is executed.
(Supplementary Note 10) In the storage control device according to any one of Supplementary Note 2, Supplementary Note 4, Supplementary Note 5, Supplementary Note 7, and Supplementary Note 8,
When receiving an instruction to write to the predetermined storage from the outside, the control unit, when copying from the write target range to the snapshot of all data is not completed, A storage control apparatus that copies to a snapshot of data and executes the writing.
(Supplementary Note 11) In the storage control device according to any one of Supplementary Note 3, Supplementary Note 4, Supplementary Note 6, Supplementary Note 7, and Supplementary Note 9,
When receiving an instruction to write to the predetermined storage from the outside, the control unit, when copying from the write target range to the snapshot of the differential data is not completed, A storage control apparatus that copies to a snapshot of data and executes the writing.
(Supplementary Note 12) A storage control program for causing a computer to create a generation backup of a predetermined storage,
A first copy step of creating at least one of a snapshot of all data in the predetermined storage and a mirror of all data in the predetermined storage at an indicated time;
A second copy step of creating at least one of a snapshot of difference data of the predetermined storage between generations and a mirror of difference data of the predetermined storage between generations after the start of the first copy step; Storage control program to be executed.
(Supplementary note 13) In the storage control program described in supplementary note 12,
The first copy step creates a snapshot of all data in the predetermined storage in the first generation,
The storage control program characterized in that the second copy step creates a mirror of difference data of the predetermined storage between generations.
(Supplementary note 14) In the storage control program according to supplementary note 12,
The first copy step creates a mirror of all data in the predetermined storage,
The storage control program characterized in that the second copy step creates a snapshot of differential data of the predetermined storage between generations.
(Supplementary Note 15) In the storage control program described in Supplementary Note 12,
The first copy step creates a snapshot of all data in the predetermined storage in the first generation, and creates a mirror of all data in the predetermined storage,
The second copy step creates a mirror of differential data of the predetermined storage between generations, and creates a snapshot of differential data of the predetermined storage between generations. .
(Supplementary Note 16) In the storage control program described in Supplementary Note 2,
After a snapshot of all the data is created by the first copy step and at least one mirror of the difference data is created by the second copy step, a restore instruction including a restore target time is received. And causing the computer to execute a restore step of reflecting the mirror of the difference data before the target time to the snapshot of all the data in the oldest order and reflecting the snapshot of the all data after the reflection to the predetermined storage. A storage control program characterized by
(Supplementary Note 17) In the storage control program described in Supplementary Note 3,
When a mirror of all the data is created by the first copy step and at least one snapshot of the differential data is created by the second copy step, a restore instruction including a restore target time is received. A storage control program for causing a computer to execute a restore step of reflecting the snapshot of the difference data after the target time to the predetermined storage in the newest order.
(Supplementary note 18) In the storage control program described in supplementary note 4,
The first copy step creates a snapshot of all the data, creates a mirror of all the data, and the second copy step creates at least one mirror of the difference data, and at least one After the snapshot of the differential data is created, and further receiving a restore instruction including a target time for restoration, it is determined whether the time of the first generation or the current time is closer to the target time, When the time of the first generation is closer to the target time, the mirror of the difference data before the target time is reflected in the snapshot of all data in the oldest order, and the snapshot of all data after the reflection is reflected in the When the current time is closer to the target time after reflecting to a predetermined storage, The storage control program, characterized in that to execute a restore step of reflecting a snapshot of the difference data to the predetermined storage in reverse chronological order to the computer.
(Supplementary note 19) A storage control method for creating a generation backup of a predetermined storage,
A first copy step of creating at least one of a snapshot of all data in the predetermined storage and a mirror of all data in the predetermined storage at an indicated time;
After the start of the first copy step, execute a second copy step of creating at least one of a snapshot of difference data of the predetermined storage between generations and a mirror of difference data of the predetermined storage between generations Storage control method.

1 is a block diagram illustrating an example of a configuration of a storage device according to a first embodiment. 6 is a table showing an example of a structure of copy session management information according to the first embodiment. 4 is a table showing an example of a structure of an LBA conversion table according to the first embodiment. 4 is a table showing an example of a structure of a generation management table according to the first embodiment. 6 is a flowchart illustrating an example of operation of generation backup start processing according to the first embodiment. 4 is a flowchart illustrating an example of operation of generation switching processing according to the first embodiment. 6 is a flowchart illustrating an example of operation of Write I / O processing during generation backup according to the first embodiment. 6 is a diagram illustrating an example of a specific operation of generation backup processing according to Embodiment 1. FIG. 6 is a flowchart illustrating an example of an operation of a restore start process according to the first embodiment. 6 is a flowchart illustrating an example of operation of I / O processing during generation restoration according to the first embodiment. 6 is a diagram illustrating an example of a specific operation of generation restore processing according to Embodiment 1. FIG. 4 is a flowchart illustrating an example of an operation of a tape backup process according to the first embodiment. 10 is a table showing an example of a structure of a generation management table according to the second embodiment. 10 is a flowchart illustrating an example of operation of generation backup start processing according to the second embodiment. 10 is a flowchart illustrating an example of operation of generation switching processing according to the second embodiment. 10 is a flowchart showing an example of operation of Write I / O processing during generation backup according to the second embodiment. FIG. 10 is a diagram illustrating an example of a specific operation of generation backup processing according to the second embodiment. 10 is a flowchart illustrating an example of an operation of a restore start process according to the second embodiment. 10 is a flowchart illustrating an example of operation of I / O processing during generation restoration according to the second embodiment. FIG. 10 is a diagram illustrating an example of a specific operation of generation restore processing according to the second embodiment. 10 is a flowchart illustrating an example of an operation of a tape backup process according to the second embodiment. FIG. 20 is a diagram illustrating an example of a specific operation of generation restore processing according to the third embodiment.

Explanation of symbols

1 storage device, 2 host, 11 CA, 12 CM, 13 disk, 21 CPU, 22 cache memory, 23 FC control unit.

Claims (6)

A storage control device for creating a generation backup of a predetermined storage for storing data,
A first copy unit that copies the data in the predetermined storage up to the designated first time point to the pre-update data storage;
A second copy unit for copying the updated data of the predetermined storage in the predetermined period after the first time point to the updated data storage;
When a restore instruction including a restore target time is received, data restoration at a specified second time point is performed using the data in the pre-update data storage and the data in the post-update data storage before the target time. A storage control apparatus comprising: a control unit that performs The storage control device according to claim 1.
The control unit causes the first copy unit to copy the entire first data of the predetermined storage at the first time point, which is the start time of the generation backup, to the pre-update data storage. After the update of the second data updated in the predetermined storage from the time when the second copy unit is instructed about the generation of the generation backup to the time when the next generation is instructed. The second copy data is created by copying to the data storage, and after the first copy data is created by the first copy unit and at least one second copy data is created by the second copy unit When the restore instruction is received later, the second copy data before the target time is reflected in the first copy data in the oldest order. Storage control apparatus characterized by reflecting the first copy data after the reflection to the predetermined storage performing the restore. The storage control device according to claim 1.
The control unit causes the second copy unit to copy the latest third data of the entire predetermined storage after the first time, which is the start time of the generation backup, to the updated data storage. Pre-update data of the fourth data updated in the predetermined storage from the time when the first copy unit is instructed about the generation of the generation backup to the time when the next generation is instructed. Is copied to the pre-update data storage, the fourth copy data is created, and the third copy data is created by the second copy unit and at least one fourth copy data is created by the first copy unit. When the restore instruction is received after the file is created, the fourth copy data after the target time are stored in the predetermined order in the newest order. The storage control device and performs the restoration by reflecting the over-di. The storage control device according to claim 1.
The control unit causes the first copy unit to copy the entire first data of the predetermined storage at the first time point, which is the start time of the generation backup, to the first storage which is the pre-update data storage. After the second data updated in the predetermined storage from the time when the second copy unit is instructed about the generation of the generation backup to the time when the next generation is instructed. The second copy data is created by copying the data to the second storage that is the updated data storage, and the second copy unit causes the second copy unit to update the latest third data of the entire predetermined storage after the first time point. To the third storage, which is the updated data storage, to create third copy data, and the first copy unit The pre-update data of the fourth data updated in the predetermined storage from the time when the backup generation is instructed to the time when the next generation is instructed is copied to the fourth storage which is the pre-update data storage. After the fourth copy data is created, the first copy data is created by the first copy unit, and at least one second copy data is created by the second copy unit, and the second copy unit When the restore instruction is received after the third copy data is created by the first copy unit and at least one fourth copy data is created by the first copy unit, the time of the first time point and the current time It is determined which is closer to the target time, and when the time at the first time point is closer to the target time, the time before the target time is When two copies of data are reflected on the first copy data in the oldest order, the first copy data after the reflection is reflected on the predetermined storage and the restoration is performed, and the current time is closer to the target time The storage control device characterized in that the fourth copy data after the target time is reflected in the predetermined storage in order of newest. A storage control program for causing a computer to create a generation backup of a predetermined storage for storing data,
The computer,
A first copy unit that copies the data in the predetermined storage up to the designated first time point to the pre-update data storage;
A second copy unit for copying the updated data of the predetermined storage in the predetermined period after the first time point to the updated data storage;
When a restore instruction including a restore target time is received, data restoration at a specified second time point is performed using the data in the pre-update data storage and the data in the post-update data storage before the target time. A storage control program that functions as a storage control device. A storage control method for causing a computer to create a generation backup of a predetermined storage for storing data,
Copy the data in the predetermined storage up to the designated first time point to the pre-update data storage,
Copy updated data of the predetermined storage in a predetermined period after the first time point to the updated data storage,
When a restore instruction including a restore target time is received, data restoration at a specified second time point is performed using the data in the pre-update data storage and the data in the post-update data storage before the target time. A storage control method for causing a computer to execute

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