JP2011076572A - Storage system, storage device, method for duplicating data stored in the storage device, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage system and the like for efficiently duplicating data. <P>SOLUTION: In the storage system 1, a first storage device 10 includes: a first allocation means 112 for constructing a virtual volume 150 constituted of blocks having a block length and a start address given in advance, from a pool 140, and for allocating a real storage area to each block; a first duplication preparing means 113 for reproducing the data stored in the virtual volume on the first storage device onto a virtual volume on the second storage device, in response to a duplication preparation request; a zero data analytical means 114 for checking whether the real storage area is allocated to each block; and a first area-releasing means 111 for releasing the real storage area of the block where no real storage area is allocated, and for transmitting a zero data notification to the second storage device 20. The second storage device receives the zero data notification, to release the real storage area of the block. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a storage apparatus, and more particularly to performing replication in a storage apparatus to which a storage area is allocated by thin provisioning.

  A thin provisioning technique is known as one technique for efficiently managing the capacity in a storage apparatus. Thin provisioning is a technology in which a logical disk with a virtual capacity that is virtually larger than the total physical capacity of hard disks is allocated to the host computer, and the actual storage area is allocated when a write request is actually received from the host computer. is there. Also, depending on the storage vendor, periodically checking whether the data in the block of the allocated storage area is all zero (this is called zero data area), if it is zero, by releasing that area, Some vendors have realized efficient use of storage space. In this case, if there is a read (Read I / O) request to the released area from the host computer, the storage apparatus returns zero, and if there is a write (Write I / O) request, the storage apparatus again allocates a new storage area. assign.

  On the other hand, replication technology is known as a technology related to storage data replication. This is a technique for creating a replica (replica) having exactly the same contents as data of a certain volume. At this time, there are two types of arrangement methods of the master volume and the replica volume, in the case where they exist in the same storage device and in the case where they are divided into different storage devices.

  As technical documents related to these, there are the following patent documents. Patent Document 1 describes an example of a method for releasing an area that can be determined to be unnecessary by thin provisioning technology. Patent Document 2 describes a technique for unifying data block lengths in old and new memories as a method of taking over stored data in a memory. Patent Document 3 discloses a technique in which a physical storage area is not allocated to a segment that is void data at the time of restoration in order to reduce waste of capacity when performing backup and restoration of data in a storage device performing thin provisioning. Is described.

JP 2005-011316 A JP 2000-137604 A Japanese Patent Laid-Open No. 2008-130080

  However, the thin provisioning function and the replication function are originally separate technologies, and therefore both are provided as independent and separate functions in the storage apparatus. For this reason, when the thin provisioning function and the replication function are used in combination, both perform data read processing separately and asynchronously with respect to the same area. That is, reading / writing data and releasing an area are not efficient.

  Moreover, the block lengths of the storage areas handled are generally not the same between the thin provisioning function and the replication function. Therefore, if a zero data area exists at the copy source, the replication function copies the zero data area to the copy destination as it is, and whether the thin provisioning function is the copy destination side and the area is the zero data area. It is determined whether or not the area is deleted, and the determination and deletion processing is not efficient. In addition, an excessive load is applied to the storage apparatus.

  Incidentally, none of the techniques described in the above-mentioned Patent Documents 1 to 3 is a combination of the thin provisioning function and the replication function, and thus does not solve the above-described problem caused by combining the two.

  An object of the present invention is to provide a storage system, a storage apparatus, and a storage content replication method for a storage apparatus that can efficiently replicate data even in an environment in which a thin provisioning function and a replication function are used together And to provide a program.

  In order to achieve the above object, a storage system according to the present invention includes first and second storage apparatuses each having a pool constructed from physical disks by RAID (Redundant Arrays of Inexpensive Disks), and first and second storage apparatuses. A storage system including a management console that transmits a replication creation request to the storage device of the second storage device, wherein the first storage device pools a virtual volume configured with blocks having a predetermined block length and start address And a first area allocating means for allocating the real storage area to each block, and the storage contents of the virtual volume on the first storage device in response to the replication creation request to the virtual volume on the second storage device First copy creation means to replicate and the storage contents of the virtual volume are replicated The zero data analysis means for checking whether or not the real storage area is allocated to each block constituting the virtual volume on the first storage device, and the real storage area of the block to which the real storage area is not allocated And first data releasing means for releasing zero data notification indicating that the real storage area is a block to which a real storage area is not assigned to a block to which the real storage area is not assigned. A virtual volume that has a function of transmitting to the second storage device, and the second storage device has a block having the same block length and start address as the first storage device given in advance from the pool Second area allocating means for constructing and allocating the real storage area to each block, and receiving zero data notification And having a second area releasing unit for releasing the real storage area of the block.

  In order to achieve the above object, a storage apparatus according to the present invention is a storage apparatus having a pool constructed from physical disks by RAID (Redundant Arrays of Inexpensive Disks), which has a block length and a start address given in advance. A volume allocation unit that allocates a real storage area to each block by constructing a virtual volume composed of blocks having a virtual volume from the pool, and a virtual volume on another storage device in accordance with a copy creation request A replica creating means for replicating, a zero data analyzing means for checking whether or not a real storage area is allocated to each block constituting the virtual volume when replicating the storage contents of the virtual volume, and a real storage area Area release means for releasing the real storage area of unallocated blocks And the replica creating means has a function of transmitting a zero data notification indicating that the real storage area is a block to which no real storage area is assigned to another storage apparatus. Features.

  In order to achieve the above object, a storage content replication method of a storage device according to the present invention includes first and second storage devices each having a pool constructed from physical disks by RAID (Redundant Arrays of Inexpensive Disks). A storage system including a management console for transmitting a copy creation request to the first and second storage devices, wherein the storage contents of the first storage device are copied to the second storage device, Each of the first and second storage apparatuses constructs a virtual volume composed of blocks having the same block length and start address given in advance from the pool, and assigns a real storage area to each block. In response to the storage device receiving a copy creation request, the first storage device It is checked whether or not a real storage area is allocated to each block constituting the virtual volume on the device. If the real storage area is not allocated to the block, the real storage area of the block is released and the first The storage device sends a zero data notification indicating that the block is a block to which no real storage area is allocated to the second storage device, and the second storage device receiving the zero data notification It is characterized by releasing the real storage area.

  To achieve the above object, a storage content replication program of a storage device according to the present invention includes first and second storage devices each having a pool constructed from physical disks by RAID (Redundant Arrays of Inexpensive Disks). , A storage system including a management console that transmits a copy creation request to the first and second storage apparatuses, and having the same block length and start address given in advance to the computer included in the first storage apparatus The virtual volume configured by the blocks is constructed from the pool, and the real storage area is allocated to each block, and the virtual volume on the first storage device is configured in response to receiving the replication creation request Check whether a real storage area is assigned to each block. And a zero data notification indicating that the block is a block to which the real storage area is not allocated and the real storage area of the block is released if the block is not allocated. And a procedure of transmitting to the storage apparatus.

  As described above, since the present invention is configured to check whether there is a block to which a real storage area is not allocated in response to a copy creation request and to release the real storage area of such a block, the thin provisioning function Read processing separately performed by the replication function can be reduced to one time. This makes it possible to efficiently replicate data even in an environment where both the thin provisioning function and the replication function are used together. A storage content replication method and program for a storage apparatus can be provided.

It is explanatory drawing which shows the structural example of the whole storage system which concerns on this embodiment. FIG. 2 is an explanatory diagram showing a more detailed configuration of the first (second) storage device shown in FIG. 1. FIG. 3 is an explanatory diagram conceptually showing the construction of a virtual volume performed in the first (second) storage apparatus shown in FIG. 1. It is explanatory drawing which shows an example of the pair setting management table shown in FIG. It is explanatory drawing which shows an example of the allocation management table shown in FIG. FIG. 2 is a flowchart illustrating a process performed by a storage device on the MV (Master Volume) side illustrated in FIG. 1 in response to a copy creation request from a management console. It is a flowchart which shows the real area release process shown as step S309 of FIG. 6 in more detail. FIG. 2 is a flowchart describing a process performed by a replica creating unit of an RV (Replica Volume) side storage apparatus that has received an event from a replica creating unit of the MV side storage apparatus shown in FIG. 1;

(First embodiment)
Hereinafter, the configuration of an embodiment of the present invention will be described with reference to FIGS.
First, the basic content of the present embodiment will be described, and then more specific content will be described.
The storage system 1 according to this embodiment includes first and second storage apparatuses 10 and 20 each having pools 140 and 240 constructed from physical disks 12 and 22 by RAID (Redundant Arrays of Inexpensive Disks), The storage system includes a management console 40 that transmits a copy creation request to the first and second storage apparatuses. The first storage device includes a first area allocating unit 112 that constructs a virtual volume composed of blocks having a block length and a start address given in advance from the pool and allocates a real storage area to each block; In response to a copy creation request, the first copy creation means 113 for copying the storage content of the virtual volume on the first storage device to the virtual volume on the second storage device, and when copying the storage content of the virtual volume , Zero data analysis means 114 for checking whether or not a real storage area is allocated to each block constituting the virtual volume on the first storage device, and a real storage area of a block to which no real storage area is allocated And first area releasing means 111 for releasing. The first replica creation unit has a function of transmitting a zero data notification indicating that the block to which the real storage area is not assigned to the second storage apparatus to the block to which the real storage area is not assigned. One of the second storage devices constructs a virtual volume composed of blocks having the same block length and start address as the first storage device given in advance from the pool, and assigns a real storage area to each block. The second area allocating means 212 for allocating and the second area releasing means 211 for receiving the zero data notification and releasing the real storage area of the block.

  In addition, when the first replica creation means replicates the contents of the virtual volume of the first storage device to the second storage device, a real storage area is included in each block constituting the virtual volume on the first storage device. If assigned, it has a function of transmitting a copy request for the block to the second storage device. On the other hand, when the second storage device receives the copy request, the second storage device copies the storage content of the block on the first storage device to the corresponding block on the second storage device. Have.

  Each of the first and second storage apparatuses has an allocation status flag indicating whether or not a real storage area is allocated to each block, and a copy difference between corresponding blocks on the first and second storage apparatuses. Allocation management tables 121 and 221 including difference flags indicating whether or not they exist are stored.

With this configuration, the storage system 1 can replicate data at high speed.
Hereinafter, this will be described in more detail.

  FIG. 1 is an explanatory diagram showing a configuration example of the entire storage system 1 according to the present embodiment. In the storage system 1, the first storage device 10 and the second storage device 20 are both connected to the same LAN (Local Area Network) 50 and are also connected to the same SAN 60. In addition to the first and second storage devices 10 and 20, the LAN 50 and SAN 60 include k host computers 31 and 32 that read and write data to and from the first and second storage devices 10 and 20 via the SAN 60. ... 3k (k is a natural number) is connected.

  In addition, a management console 40 that issues management commands to the first and second storage apparatuses 10 and 20 is also connected to the LAN 50. The connection from the management console 40 to the first and second storage apparatuses 10 and 20 is only the LAN 50 and not the SAN 60. In a CPU 41 (Central Processing Unit) provided in the management console 40, a copy creation request means 42, which is a computer program that issues a replication command to the first and second storage apparatuses 10 and 20, is executed.

  In addition to the LAN 50 and the SAN 60, the first and second storage apparatuses 10 and 20 are also connected by a replication link 70 that directly connects these storage apparatuses to each other. The replication link 70 directly connects the storage apparatuses 10 and 20 and serves as a transfer path for data to be copied when executing replication. Although FIG. 2 shows an example in which the first and second storage devices 10 and 20 are physically separate devices, they may be the same device.

  The first storage device 10 includes a microcomputer 11 and a physical disk 12. Similarly, the second storage device 20 includes a microcomputer 21 and a physical disk 22. Here, since the first storage device 10 and the second storage device 20 have the same configuration and the same functional means operate, the first storage device 10 will be described first.

  FIG. 2 is an explanatory diagram showing a more detailed configuration of the first storage device 10 shown in FIG. The microcomputer 11 includes a CPU 101 that is a main body that executes a computer program, a RAM (Random Access Memory) 102 that temporarily stores a program and data in operation, and a ROM that is a nonvolatile storage device that stores the program and data. (Read Only Memory) 103, and a network interface card (NIC) 104 that exchanges data with other devices via the LAN 50, the SAN 60, and the replication link 70.

  The physical disk 12 is composed of n hard disk (HDD) devices 12a, 12b,..., 12n (n is a natural number), and these HDD devices are collectively referred to. Similarly, the physical disk 22 includes m hard disk (HDD) devices 22a, 22b,..., 22m (m is a natural number), and these HDD devices are collectively referred to. Note that m and n and the number k of the host computers described above may be the same value or different values.

  In the CPU 101, an area release unit 111, an area allocation unit 112, a copy creation unit 113, a zero data analysis unit 114, and a host I / O control unit 115 are each executed as a computer program. The RAM 102 stores work data such as an assignment management table 121 and a pair setting management table 122. Details of these functional means and data will be described later.

  The second storage device 20 also has the same configuration as the first storage device 10 described above. The computer resources included in the microcomputer 21 of the second storage device 20 and the functional means and data operating therein are the same as those described above for the first storage device 10 and have the same names and operations, and reference numbers are +100 respectively. Shall be.

  FIG. 3 is an explanatory diagram conceptually showing the construction of a virtual volume performed in the first storage device 10 (or the second storage device 20) shown in FIG. In the first storage device 10, the area allocation unit 112 constructs a pool 140 from the physical disk 12 by RAID (Redundant Arrays of Inexpensive Disks), and allocates a virtual volume 150 thereon. Similarly, in the second storage device 20, the area allocation unit 212 constructs a pool 240 from the physical disk 22 by RAID and allocates a virtual volume 250 thereon. Hereinafter, the virtual volume 150 may be referred to as MV (Master Volume) and the virtual volume 250 may be referred to as RV (Replica Volume). Further, in the meaning of the virtual volume 150 side or the virtual volume 250 side, they may be referred to as the MV side and the RV side, respectively.

  The virtual volumes 150 and 250 can virtually have a capacity larger than the actual capacity physically allocated on the pools 140 and 240 by thin provisioning. The virtual volumes 150 and 250 have an actual capacity of zero at the beginning of construction. Actual storage areas are allocated on the pools 140 and 240 at the timing when a write (Write I / O) request is actually received from the host computers 31 to 3n.

  Further, each block in the virtual volume is mapped 1: 1 to a block in the pool constituting the virtual volume if an area is allocated. For example, an arrow indicates that the first block in the virtual volume 150 is mapped to the first block in the pool 140.

  The virtual volumes 150 and 250 are paired by the replication function. Information regarding pair setting is managed in the pair setting management tables 122 and 222. FIG. 4 is an explanatory diagram showing an example of the pair setting management tables 122 and 222 shown in FIG. The pair setting management tables 122 and 222 have the same contents on the MV side and the RV side, both of which are the copy source device name 122a (222a), the copy source device number 122b (222b), and the copy destination device name. 122c (222c) and a copy destination apparatus number 122d (222d) are stored.

  The data shown in the example of FIG. 4 is paired with the virtual volume 150 (MV01) of the storage device 10 (MV) as the copy source and the virtual volume 250 (RV01) of the storage device 20 (RV) as the copy destination. Is shown.

  Here, in the storage apparatuses 10 and 20, the data block management unit (block length and start address) managed by the replication function and the data block management unit (block length and start address) managed by the thin provisioning function are: Must match. In other words, the replication function and the thin provisioning function operate based on each block of the virtual volume and the pool.

  At this time, when replication is performed using the virtual volume 150 as the copy source and the virtual volume 250 as the copy destination, the first block in the virtual volume 250 corresponds to the first block in the virtual volume 150. Similarly, the second block in the virtual volume 150 corresponds to the second block in the virtual volume 250. The same applies thereafter.

  FIG. 5 is an explanatory diagram showing an example of the allocation management tables 121 and 221 shown in FIG. The allocation management table 121 has columns of a virtual volume number 121a, a virtual volume address 121b, an allocation state 121c, a pool number 121d, a pool address 121e, and a difference presence / absence flag 121f. Since the assignment management table 221 also has the same data structure as the assignment management table 121, it is assumed that the reference number of each column is +100 of the reference number of each column of the assignment management table 121.

  The virtual volume number 121a is an identifier that uniquely identifies the virtual volume. The virtual volume number 121a corresponds to the copy source volume 122b (222b) of the pair setting management table 122 (222). The in-virtual volume address 121b is the start address of the block in the virtual volume.

  The allocation state 121c is a flag indicating whether a real storage area in the pool is allocated to the block in the virtual volume. There are two types of values, “1 (= allocated)” and “0 (= unallocated)” in the allocation state. “1” indicates that a real storage area is allocated, and “0” indicates that a real storage area is not allocated.

  The pool number 121d is an identifier that uniquely identifies the pool. The in-pool address 121e is a start address of the block (that is, a real storage area) in the pool. The difference presence / absence flag 121f is a flag indicating whether or not there is a copy difference between the copy source block (which corresponds to each row of the allocation management table 121) and the copy destination block.

  The difference presence / absence flag 121f includes two types of values, “1 (= present)” and “0 (= none)”. When the data in the copy source block is updated, the value of the difference presence / absence flag is “1” until the update is reflected in the copy destination block. When the update is reflected in the copy destination block, it becomes “0”.

  In the example shown in FIG. 5, for example, the first block (address 0x0000000) of the virtual volume 150 is assigned the first block (address 0x0000000) of the pool 140, and there is a copy difference with the copy destination block. (The difference presence / absence flag is “present”).

  The copy creation unit 113 receives a copy creation request from the management console 40, acquires pair information from the pair setting management table 122, and copies the storage device in which the copy destination volume exists from the pair information and the information in the assignment management table 121. A notification is sent to the creation unit, and the notification is received. The zero data analysis unit 114 and the area release unit 111 are called, and the data received from the copy creation unit of the copy source volume is copied to the copy destination volume. The copy creation unit 213 also has the same function as the copy creation unit 113.

  The zero data analysis unit 114 is called from the copy creation unit 113, analyzes whether the data corresponding to the block of the designated virtual volume is zero data (null), and returns the analysis result to the copy creation unit 113. The zero data analysis unit 214 has the same function as the zero data analysis unit 114.

  The area releasing unit 111 is called from the replica creating unit 113, releases the real storage area allocated to the pool corresponding to the block of the designated virtual volume, updates the data in the allocation management table 121 after releasing the area, The execution result of the release process is returned to the copy creation means 113. The area release unit 211 also has the same function as the area release unit 111.

  The host I / O control means 115 and 215 process read (Read I / O) requests and write (Write I / O) requests from the host computers 31 to 3k.

  The area allocation unit 112 is called from the host I / O control unit 115 and allocates a real storage area from the pool when the block allocation state of the designated virtual volume is “unallocated”, and manages the allocation after the allocation of the area. The data in the table 121 is updated, and the execution result of the area allocation process is returned to the host I / O control means 115. The area allocation unit 212 has the same function as the area allocation unit 112.

  Now, in the management console 40, the copy creation requesting unit 42 has issued a copy creation (replication) request from the virtual volume 150 to 250. At this time, the copy creation request unit 42 transmits information for uniquely specifying the copy source and copy destination volumes and information for specifying the copy creation method (full copy or differential copy) together with the copy creation request.

  Upon receiving a replication creation request from the management console 40 to the virtual volume 150 (MV) to 250 (RV), the replication creation unit 113 refers to the allocation management table 121 and applies to each block constituting the virtual volume 150. Call zero data analysis means 114.

  The zero data analysis unit 114 checks whether or not a real storage area is allocated to the block. If so, the data in the real storage area is checked next. If all the data is zero data, information indicating that the data is zero data is returned to the copy creation means 113. When receiving the information that the data is zero data, the replica creation unit 113 calls the area release unit 111 for the block on the MV side.

  The area releasing unit 111 releases an actual storage area for storing data corresponding to the block. Next, the allocation state for the block in the allocation management table 121 is changed from “allocated” to “unallocated”. Next, based on the pair information in the pair setting management table 122, the copy source copy creation unit 113 sends the block on the MV side corresponding to the block on the RV side to the copy destination copy creation unit 213. Send a notification to the effect.

  When receiving the notification that the copy is not made, the copy destination copy creation unit 213 checks the allocation state 221c of the block on the RV side. In the case of 1 (allocated), the area releasing unit 211 is called for the block on the RV side.

  The area releasing unit 211 releases an actual storage area for storing data corresponding to the block. Next, the allocation state 221 c for the block in the allocation management table 221 is updated from 1 (allocated) to 0 (unallocated), and control is returned to the replica creation unit 213.

  The replica creation unit 213 updates the value of the difference presence / absence flag 221f for the block in the allocation management table 221 to 0. Thereafter, the replica creation unit 213 sends a notification of area release completion to the block on the RV side to the copy creation unit 113. Upon receiving the notification, the replica creation unit 113 updates the value of the difference presence / absence flag 221f for the block in the allocation management table 121 to 0.

  In this way, with the trigger of replication, it is analyzed whether or not each block of the copy source (MV side) is zero data, and if there is a block of zero data, for both blocks on the MV side and RV side To free up real storage.

  FIG. 6 is a flowchart describing the processing performed by the MV-side storage apparatus 10 shown in FIG. 1 in response to a copy creation request from the management console 40. First, the copy creation request unit 42 of the management console 40 issues a copy creation request to the storage apparatus 10 (step S301). When the copy creation unit 113 of the storage apparatus 10 receives this request, the copy creation unit 113 refers to the allocation management table 121, and performs steps S302 to S310 for all blocks constituting the copy source volume (MV). Repeat the steps.

  After proceeding to the next block (step S302), the copy creation means 113 checks the copy creation method included in the copy creation request (step S303). In the case of differential copy (step S303: NO), the assignment management table 121 is checked. The difference presence / absence flag is referenced to check whether there is a copy difference in the block (step S308). If there is no difference, that is, the difference presence / absence flag 121f = 0 (step S308: NO), it is checked whether the next block exists (step S310), and if it exists, the process returns to step S302 to repeat the process. .

  If there is a difference (step S308: YES) or if the copy creation method is full copy (step S303: YES), whether the real storage area has been allocated to the block on the MV side, that is, the allocation state It is checked whether 121c = 1 (step S304). At this time, the replica creation unit 113 passes the information on the virtual volume number 121a and the virtual volume address 121b to the zero data analysis unit 114.

  If the real storage area for the block on the MV side has already been allocated (step S304: YES), the zero data analysis unit 114 performs the processing based on the information of the virtual volume number 121a and the in-virtual volume address 121b of the allocation management table 121. It is analyzed whether all the data in the block is zero (zero data) (step S 305), and the result is returned to the copy creation means 113.

  If the data is zero data (step S305: YES), the replica creation unit 113 calls the area release unit 111 and performs the real area release process of the block (step S306). At this time, the replica creation unit 113 passes the information on the virtual volume number 121a and the virtual volume address 121b to the area release unit 111 as information for uniquely specifying the block of the copy source volume.

  When the real storage area for the block on the MV side is unallocated (step S304: NO) and after the area release process (step S306) is completed, the copy creation unit 113 sends a copy destination (RV) to the copy creation unit 213. ) Of the virtual volume number 221a and the in-virtual volume address 221b and the event type (zero data notification in this case) are notified (step S307).

  FIG. 7 is a flowchart showing in more detail the real area releasing process shown as step S306 in FIG. First, the area releasing unit 111 performs a real area releasing process on the block of the designated virtual volume (step S351). Subsequently, the allocation management table 121 is referred to, and the value of the allocation state 121c of the block row of the virtual volume is changed to “unallocated” (step S352). Thereafter, control is returned to the replica creation means 113.

  If the data is not zero data in step S305 in FIG. 6 (step S305: NO), the copy creation unit 113 sends the copy destination virtual volume (RV) to the copy creation unit 213 of the copy destination storage apparatus 20. The information, the address information in the copy destination virtual volume, the copy target data, and the event type (here, copy process request) are transmitted, and the copy process request event is notified (step S309). Here, the information of the copy destination virtual volume can be acquired from the pair setting management table 222. Further, the information on the address in the copy destination virtual volume is obtained using the characteristic that it is the same as the address in the copy source virtual volume.

  FIG. 8 is a flowchart describing the processing performed by the replica creating unit 213 of the RV side storage apparatus 20 that has received an event from the replica creating unit 113 of the MV side storage apparatus 10 shown in FIG. Here, the event received by the copy creation unit 213 from the copy creation unit 113 is one of a copy processing request (step S309 in FIG. 6) and a zero data notification (step S307 in FIG. 6).

  Upon receiving an event from the copy creation unit 113 (step S401), the copy creation unit 213 checks what the event is (step S402). The case of zero data notification will be described later. When this event type is a copy processing request (step S402: NO), the copy creation unit 213 refers to the assignment management table 221 from the copy destination virtual volume information and address information passed from the copy creation unit 113, and It is checked whether or not the real storage area is not allocated to the corresponding block (step S411).

  If it is not allocated (step S411: YES), the replication allocation unit 212 allocates a real storage area to the corresponding block and sets the allocation state 221c of the allocation management table 221 to “allocated” (= 1) ( Step S412). After the area allocation is completed or when the allocation has already been performed (step S411: NO), a data copy process is performed on the corresponding block (step S413).

  The copy process in step S413 is performed on the first block (address in virtual volume: 0x0000000) of the copy destination virtual volume 250 corresponding to the first block (address in virtual volume: 0x0000000) of the copy source virtual volume 410, for example. Do. After completing the copy process, the copy creation unit 213 refers to the allocation management table 221 and sets the difference presence flag for the corresponding block to “none” (step S414). Thereafter, the copy creation unit 213 returns copy completion to the copy creation unit 113 (step S415).

  If the event type is zero data notification in step S402 (step S402: YES), the copy creation unit 213 reads the allocation management table 221 from the copy destination virtual volume information and address information passed from the copy creation unit 113. It is checked whether or not the real storage area has been allocated to the corresponding block (step S403). If not assigned (step S403: NO), the process proceeds to step S406, which will be described later.

  When the real storage area has been allocated (step S403: YES), a real area release process is performed for the block (step S404). Details of the processing shown in step S404 are the same as the processing shown in FIG. Thereafter, the copy creation means 213 refers to the allocation management table 221 and sets the difference presence flag for the block to “None” (step S405), and returns the area release completion to the copy creation means 113 (step S406).

  In this embodiment, as described above, triggered by a copy creation request, it is analyzed whether there is a zero data block of the copy source volume (MV side), and if there is a zero data block, both the MV side and the RV side are concerned. The real storage area is simultaneously released for the block.

(Overall operation of the first embodiment)
Next, the overall operation of the above embodiment will be described. The storage content replication method of the storage system according to the present embodiment transmits a replication creation request to the first and second storage devices each having a pool constructed from physical disks by RAID, and the first and second storage devices. The storage system includes a management console that replicates the storage contents of the first storage device to the second storage device. In this storage content duplication method, the first and second storage apparatuses respectively construct virtual volumes configured by blocks having a block length and a start address given in advance from the pool, and real storage areas are provided in the respective blocks. In response to the first storage apparatus receiving a copy creation request (FIG. 6: step S301), a real storage area is allocated to each block constituting the virtual volume on the first storage apparatus. (FIG. 6: Step S304) and if the real storage area is not allocated to the block, the real storage area of the block is released (FIG. 6: Step S306). Zero data notification indicating that the block is a block to which no real storage area is allocated. Transmitted to the storage device (FIG. 6: step S307), the second storage apparatus that received this zero data notification, releases the real storage area of the block (FIG. 8: Step S404).

Here, each of the above-described operation steps may be programmed to be executable by a computer, and may be executed by a microcomputer of each storage device, which is a computer that directly executes each of the steps. In the present embodiment, the case where the allocated area is zero data has been described. However, the present invention can be similarly applied to data other than zero (eg, all data is 1).
With this configuration and operation, the present embodiment has the following effects.

  The first effect is that the number of reads to the same real storage area, which is performed for creating a replica by the replication function and releasing a zero data area by the thin provisioning function, can be reduced from two times to one time.

  The reason for this is that in the present invention, the data block management unit managed by the thin provisioning function and the replication function is matched, and the zero data area is released at the time of replication creation, so that data can be read once. This is because it can be used for both the check process for releasing the zero data area and the copy process for creating a replica.

  The second effect is that the overhead of the zero data analysis processing can be reduced by analyzing whether or not the data in the block is zero data at the time of creating the replica, compared to the zero data analysis processing by the known technology of the thin provisioning function.

  The reason is that, in the present invention, by making the management units of the data blocks managed by the thin provisioning function and the replication function coincide with each other, the area can be always released if all the data in the block is zero.

  The third effect is that, when used in combination with the replication function, if there is a block of zero data at the copy source, the area can be immediately released even to the copy destination block.

  The reason for this is that in the present invention, when the existence of a zero data block is detected at the copy source, the copy destination block area is also immediately released during the replication process. This is because there is no need to wait for the area release processing to be performed at the copy destination.

  In the present embodiment, as shown in FIG. 1, the first and second storage apparatuses 10 and 20 are connected not only by the LAN 50 and the SAN 60 but also by the replication link 70, and the first link is made via the replication link 70. The data can be copied from the storage device 10 to the second storage device 20 at high speed. However, since the use of the replication link 70 itself is not within the scope of the present invention, for example, data may be copied via the SAN 60.

  The present invention has been described with reference to the specific embodiments shown in the drawings. However, the present invention is not limited to the embodiments shown in the drawings, and any known hitherto provided that the effects of the present invention are achieved. Even if it is a structure, it is employable.

  The present invention can be applied to a storage apparatus to which a storage area is allocated by thin provisioning, and exhibits an excellent effect particularly when replication is performed using such a storage apparatus.

DESCRIPTION OF SYMBOLS 1 Storage system 10 1st storage apparatus 20 2nd storage apparatus 11, 21 Microcomputer 12, 12a, 12b, 12m, 22, 22a, 22b, 22n Physical disk 31, 32, 3k Host computer 40 Management console 41 CPU
42 Copy creation request means 50 LAN
60 SAN
70 Replication link 101, 201 CPU
102, 202 RAM
103, 203 ROM
104, 204 NIC
111, 211 Area release means 112, 212 Area allocation means 113, 213 Replication creation means 114, 214 Zero data analysis means 115, 215 Host I / O control means 121, 221 Allocation management tables 122, 222 Pair setting management tables 140, 240 Pool 150, 250 Virtual volume

Claims (8)

The storage system includes first and second storage apparatuses each having a pool constructed from physical disks by RAID (RAID), and a management console that transmits a replication creation request to the first and second storage apparatuses. And
The first storage device is
First area allocating means for constructing a virtual volume constituted by blocks having a block length and a start address given in advance from the pool and allocating a real storage area to each of the blocks;
First copy creation means for copying the storage contents of the virtual volume on the first storage device to the virtual volume on the second storage device in response to the copy creation request;
Zero data analysis means for checking whether a real storage area is allocated to each block constituting the virtual volume on the first storage device when replicating the storage content of the virtual volume;
A first area releasing means for releasing the real storage area of the block to which no real storage area is allocated;
The first replica creation means has a function of transmitting, to the second storage device, a zero data notification indicating that the block to which no real storage area is assigned is a block to which no real storage area is assigned. And
The second storage device is
A second area in which a virtual volume composed of blocks having the same block length and start address as the first storage apparatus given in advance is constructed from the pool and a real storage area is allocated to each block Assigning means;
And a second area releasing means for releasing the real storage area of the block in response to the notification of zero data. Each block constituting the virtual volume on the first storage device when the first replica creation means replicates the contents of the virtual volume of the first storage device to the second storage device If a real storage area is allocated to the second storage device, the block has a function of transmitting a copy request for the block to
When the second storage device receives the copy request, the second storage device has second copy creating means for copying the storage content of the block on the first storage device to the corresponding block on the second storage device. The storage system according to claim 1, wherein:   Each of the first and second storage devices includes an allocation status flag indicating whether a real storage area is allocated to each of the blocks, and a corresponding block on the first and second storage devices. The storage system according to claim 1 or 2, wherein an allocation management table including a difference flag indicating whether or not a copy difference exists is stored. A storage device having a pool constructed from physical disks by RAID (RAID),
Area allocation means for constructing a virtual volume constituted by blocks having a block length and a start address given in advance from the pool and allocating a real storage area to each of the blocks;
A copy creation means for copying the storage content of the virtual volume to the virtual volume on another storage device in response to the copy creation request;
Zero data analysis means for checking whether a real storage area is allocated to each block constituting the virtual volume when replicating the storage contents of the virtual volume;
An area release means for releasing the real storage area of the block to which no real storage area is allocated;
The replica creating means has a function of transmitting a zero data notification indicating that a block to which a real storage area is not assigned to a block to which no real storage area is assigned, to the other storage device. Storage device.   5. The area releasing unit has a function of releasing a real storage area of a block corresponding to the zero data notification in response to receiving the zero data notification from another storage apparatus. The storage device described in 1.   A function of transmitting a copy request for the block to the other storage device if the replica creating means allocates a real storage area to each block constituting the virtual volume when replicating the contents of the virtual volume; 6. The method according to claim 4, further comprising a function of copying the storage contents of a block corresponding to the copy request to a corresponding block in response to receiving the copy request from another storage device. The storage device described. A storage system including first and second storage apparatuses each having a pool constructed from physical disks by RAID (RAID) and a management console that transmits a replication creation request to the first and second storage apparatuses. A method of replicating the storage content of the first storage device to the second storage device,
Each of the first and second storage devices constructs a virtual volume composed of blocks having the same block length and start address given in advance from the pool and allocates a real storage area to each of the blocks. ,
In response to the first storage device receiving the replication creation request, it checks whether a real storage area is allocated to each block constituting the virtual volume on the first storage device. ,
If no real storage area is allocated to the block, the real storage area of the block is released, and the first storage device notifies the block that the real storage area is not allocated. To the second storage device,
The storage content duplication method of the storage system, wherein the second storage device that has received the zero data notification releases the real storage area of the block. A storage system including first and second storage apparatuses each having a pool constructed from physical disks by RAID (RAID) and a management console that transmits a replication creation request to the first and second storage apparatuses. In the computer included in the first storage device,
A procedure for constructing a virtual volume composed of blocks having the same block length and start address given in advance from the pool and allocating a real storage area to each block;
In response to receiving the copy creation request, a procedure for checking whether a real storage area is allocated to each block constituting the virtual volume on the first storage device;
If the real storage area is not assigned to the block, the real storage area of the block is released, and a zero data notification indicating that the block is a block to which the real storage area is not assigned is sent to the second storage device A storage content duplication program of a storage system, characterized in that:

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