JP4905810B2 - Storage device, area allocation method, and program - Google Patents

Description

  The present invention relates to an area allocation method for a virtual logical disk configured in a storage apparatus, a storage apparatus capable of executing this method, and a program.

  There is a storage device represented by a disk array device, in which a RAID is configured by a set of a plurality of physical disks, this is handled as a large capacity disk, and a plurality of logical disks are created therein. In recent years, thin provisioning technology has attracted attention in the field of storage devices.

  Thin provisioning technology configures a disk pool area from a group of physical disks, virtualizes the capacity of the logical disk in a storage device that configures a logical disk from the disk pool area, and allocates the area on demand according to data writing Technology. Thin provisioning technology tends to increase in demand from the viewpoint of capacity efficiency, ease of introduction / operation, and ecology.

  However, compared with the operation of a storage device that does not use the conventional thin provisioning technology, the storage device that uses the thin provisioning technology causes performance degradation. Therefore, a technology that prevents performance degradation is required as a requirement. This will be described below.

  In a conventional storage apparatus that does not use the thin provisioning technology, a physical disk area is allocated when a logical disk is configured. On the other hand, in a storage apparatus using the thin provisioning technology, an area is allocated in accordance with the writing of data to the logical disk.

  Therefore, the allocation status of the area to the logical disk is confirmed at the timing when the data write request is made. If there is an unallocated area, an operation of allocating the area is necessary. For this reason, the storage apparatus using the thin provisioning technology has a problem that the I / O response deteriorates.

  In addition, a storage apparatus using the thin provisioning technology secures an area at the timing when a write request is issued from each host computer. For this reason, since areas are allocated to the respective logical disks in accordance with the allocation order by writing, the disk pool areas may be fragmented without being continuously secured. This also causes a problem that the I / O response deteriorates.

  As a technique to prevent I / O response deterioration, the allocation unit of the logical area to be allocated from the disk pool area is specified for each logical disk, and the allocation unit is increased for the logical disk for which performance is prioritized. There are known techniques to prevent fragmentation of the regions. However, the above technique requires another setting of allocation units as many as the number of logical disks constructed in the disk pool, which causes another problem of increased management costs.

As a technique for solving these problems, there is a technique disclosed in Patent Document 1. In the technique disclosed in Patent Document 1, first, a plurality of disk pool areas having different allocation units are created. When a write request is issued from the host computer to the logical disk, an optimal disk pool area to be allocated is selected according to the I / O size for which the write request has been made, and the allocation size is determined. . For this reason, according to the technique disclosed in Patent Document 1, it is considered that performance degradation (I / O response) is prevented.
JP 2007-265270 A

  However, the technique disclosed in Patent Document 1 has the following problems. The first point is that when there are different I / O patterns for one logical disk according to the operation mode, if the allocation is performed according to the I / O size, the I / O pattern at the time of the first writing is used as a reference. Therefore, the optimum assignment is not always performed. In this case, the I / O response is deteriorated.

  The second point is that allocation is performed according to the I / O size, and a large disk pool area is always allocated when the I / O size is large. It is. In this case, the volumetric efficiency is lowered.

  An object of the present invention is to solve the above problems and reduce degradation of I / O response when different I / O patterns exist for one logical disk when thin provisioning technology is applied. Another object of the present invention is to provide a storage device, a storage area allocation method, and a program that can improve volumetric efficiency.

To achieve the above object, a storage apparatus according to the present invention is a storage apparatus that constructs a virtual logical disk in a disk pool formed by a group of physical disks,
In response to a data write request from an external host computer, a data area for writing the data is secured in the disk pool, the data is written, and the I / O pattern of the data is determined. , Data writing part,
When the data writing unit requests allocation of a disk pool area when the data writing unit secures the data area, it is used as the data area according to the allocation policy set in the logical disk. A disk pool area allocation unit for allocating the disk pool area;
And an allocation policy management unit that changes an allocation policy set in the logical disk according to the I / O pattern determined by the data writing unit.

In order to achieve the above object, an area allocation method according to the present invention is an area allocation method for allocating a disk pool area when constructing a virtual logical disk in a disk pool formed of physical disk groups. Because
(A) in response to a data write request from an external host computer, securing a data area for writing the data in the disk pool, and writing the data;
(B) determining an I / O pattern of the data; and
(C) When allocation of a disk pool area becomes necessary when the data area is secured in the step (a), it is used as the data area according to an allocation policy set for the logical disk. Allocating the disk pool area
(D) changing the allocation policy set in the logical disk in accordance with the I / O pattern determined in the step (a).

Furthermore, in order to achieve the above object, the program according to the present invention causes a computer to allocate a disk pool area when constructing a virtual logical disk in a disk pool formed of physical disk groups. The program of
In the computer,
(A) in response to a data write request from an external host computer, securing a data area for writing the data in the disk pool, and writing the data;
(B) determining an I / O pattern of the data; and
(C) When allocation of a disk pool area becomes necessary when the data area is secured in the step (a), it is used as the data area according to an allocation policy set for the logical disk. Allocating the disk pool area
(D) The step of changing the allocation policy set in the logical disk in accordance with the I / O pattern determined in the step (a) is executed.

  As described above, according to the present invention, when thin provisioning technology is applied, it is possible to reduce degradation of I / O response when different I / O patterns exist for one logical disk. Further, according to the present invention, it is possible to improve the volumetric efficiency.

(Embodiment)
Hereinafter, a storage apparatus, an area allocation method, and a program according to an embodiment of the present invention will be described with reference to FIGS. First, the configuration of the storage apparatus according to the embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing a configuration of a storage apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the logical disk area management table shown in FIG. FIG. 3 is a diagram showing an example of the disk pool area management table shown in FIG. FIG. 4 is a diagram showing an example of the allocation policy management table shown in FIG. FIG. 5 is a diagram showing an example of the allocation policy setting table shown in FIG. FIG. 6 is a diagram showing an example of the I / O pattern integration table shown in FIG.

  The storage system shown in FIG. 1 includes the storage apparatus 100 according to the present embodiment, a host computer 300, a host computer 310, and a host computer 320. The storage apparatus 100 uses a thin provisioning technology. The storage apparatus 100 configures a disk pool 200 from the physical disk group 110 and constructs a virtual logical disk (logical disk group 120) in the disk pool 200.

  The host computers 300, 310, and 320 are connected to the storage apparatus 100 in a SAN environment. The host computers 300, 310, and 320 use a virtual logical disk group 120 constructed on the storage apparatus 100.

  As illustrated in FIG. 1, the storage apparatus 100 includes a data writing unit 130, a disk pool area allocation unit 140, and an allocation policy management unit 150. Among these, the data writing unit 130 secures a data area for writing data in the disk pool 200 in response to a data write request from the external host computer 300, 310, 320, and executes the data write. To do. In addition, when there is a data write request, the data writing unit 130 determines a data I / O pattern.

  The disk pool area allocation unit 140 allocates a disk pool area to be used as a data area according to the allocation policy set for the logical disks 120a to 120c when the data writing unit 130 secures the data area. The allocation by the disk pool area allocation unit 140 is performed when the data writing unit 130 requests allocation of a disk pool area.

  The allocation policy management unit 150 changes the allocation policy set in the logical disks 120a to 120c according to the I / O pattern (for example, sequential I / O and random I / O) determined by the data writing unit 130. To do. In FIG. 1, three logical disks are shown as logical disks. However, in the present embodiment, the number of logical disks is not limited.

  Thus, in the storage apparatus 100, a disk pool area is allocated according to the allocation policy set for the logical disk, and this allocation policy is changed according to the I / O pattern. Therefore, according to the storage apparatus 100, even when different I / O patterns exist for one logical disk, optimal allocation is performed, and deterioration of I / O response is reduced.

  In the storage apparatus 100, since an allocation policy is set according to the I / O pattern, a small disk pool area can be allocated even when the I / O size is large. Therefore, according to the storage apparatus 100, the volumetric efficiency can be improved.

  Here, the configuration of the storage apparatus 100 will be described more specifically. The storage apparatus 100 further includes a data area relocation unit 160, a logical disk area management table 170, a disk pool area management table 180, an allocation policy management table 190, an I / O pattern integration table 210, and an allocation policy setting table 220. ing.

  In the present embodiment, when there is a data write request from the host computer 300, 310, 320, the data writing unit 130 first refers to the logical disk area management table 170 (see FIG. 2) and can write the data. The presence or absence of a new area (data area).

  A logical disk area management table 170 shown in FIG. 2 is a table held by the storage apparatus 100. The logical disk area management table 170 is constructed with items of a logical disk ID, a logical disk address, and an assigned physical block ID. In other words, the logical disk area management table 170 lists the unique number of the virtual logical disk, the address of the logical disk to which the disk pool area is allocated, and the ID of the physical block allocated to the logical disk. It is a table.

  If there is no writable area in the logical disks 120a to 120c, the data writing unit 130 requests the disk pool area allocation unit 140 to allocate an area from the disk pool 200. Further, when the data pool is secured by the disk pool area allocation unit 140 allocating the disk pool area to any one of the logical disks (120a to 120c), the data writing unit 130 allocates data to this logical disk. Perform writing.

  In this embodiment, the data writing unit 130 subsequently determines the I / O size and I / O pattern (access method) of the data to be written, and updates the I / O pattern integration table 210 (see FIG. 6). To do.

  An I / O pattern integration table 210 illustrated in FIG. 6 is a table held by the storage apparatus 100. The I / O pattern integration table 210 is constructed with items of I / O size, I / O pattern (access method), and logical disks (LD01 to LD03) configured in the disk pool 200. The I / O pattern integration table 210 is a list obtained by counting I / O patterns when data is written for each logical disk.

  The disk pool area allocation unit 140 operates on the storage apparatus 100. In this embodiment, when the disk pool area allocation unit 140 receives a disk pool area allocation request from the data writing unit 130, the disk pool area allocation unit 140 refers to the allocation policy management table 190 (see FIG. 4). Then, the disk pool area allocation unit 140 allocates a data area according to the allocation policy of the disk pool 200 set for each logical disk (120a to 120c) with reference to this. Thereafter, the disk pool area allocation unit 140 updates the logical disk area management table 170 (see FIG. 2) and the disk pool area management table 180 (see FIG. 3).

  An allocation policy management table 190 illustrated in FIG. 4 is a table held by the storage apparatus 100. The allocation policy management table 190 is constructed with the logical disk ID, the allocation policy, and the allocation unit set for each allocation policy as items. The allocation unit means the size of the disk pool area that can be allocated at one allocation. The allocation policy management table 190 is a table that lists combinations of allocation policies set for each logical disk and allocation units.

  Also, as shown in FIG. 4, in this embodiment, two allocation policies (speed-oriented or capacity-oriented) with different allocation units are set as the allocation policy. The allocation unit in the priority on speed is set larger than the allocation unit in the priority on capacity. The relationship between each allocation policy and the allocation unit is as shown in the allocation policy setting table 220 shown in FIG. The allocation policy setting table 220 shown in FIG. 5 is a table that lists combinations of allocation policies and allocation units.

  The disk pool area management table 180 shown in FIG. 3 is also a table held by the storage apparatus 100. The disk pool area management table 180 is constructed with items of physical block ID, disk pool address, assigned logical disk ID, and assignment flag. The disk pool area management table 180 is a table that lists which physical disk ID is assigned to which logical block (120a to 120d) and each physical block constituting the physical disk has been assigned. is there.

  The allocation policy management unit 150 operates on the storage apparatus 100. In the present embodiment, the allocation policy management unit 150 refers to the I / O pattern integration table 210 (see FIG. 6) and the allocation policy management table 190 (see FIG. 4) periodically. Then, the allocation policy management unit 150 compares the number integrated for each type of I / O pattern with the set threshold value, and is set in the logical disks (120a to 120c) based on the comparison result. Change the allocation policy. In FIG. 6, “★” indicates a threshold value.

  Specifically, the allocation policy management unit 150 temporarily changes the allocation policy when there is a logical disk in which the total number of I / O patterns exceeds a preset threshold, To change. For example, when the allocation policy of LD01 shown in FIG. 6 is set to emphasize capacity, the integrated number of “I / O” in which the I / O size is 1 or less and the I / O pattern is randomly set is It is assumed that the threshold value is “25”. In this case, the allocation policy management unit 150 changes the allocation policy of LD01 to emphasize speed, and increases the allocation unit. As a result, a decrease in I / O response is suppressed. After the change, the allocation policy management unit 150 updates the allocation policy management table 190.

  Further, when the integrated number of I / O patterns falls below the threshold value, the allocation policy management unit 150 changes the allocation policy of the logical disk again and restores the allocation unit to the original. Thereafter, the allocation policy management unit 150 updates the allocation policy management table 190 again.

  The data area rearrangement unit 160 operates on the storage apparatus 100 and periodically refers to the logical disk area management table 170 (see FIG. 2) and the allocation policy management table 190 (see FIG. 4) to determine the disk pool area. Relocate the data area to be used.

  In the case of a logical disk in which the allocation policy is set to emphasize speed, the data area relocation unit 160 has a plurality of data areas allocated to each of a plurality of discontinuous physical blocks to each of a plurality of continuous physical blocks. Rearrange multiple data areas to be allocated,

  Specifically, when the allocation policy is set to emphasize speed, the data area relocation unit 160 allocates the physical block IDs of the logical disks discontinuously as data areas, and further allows allocation units that can be continuous. Determine if exists. If it exists, the data area relocation unit 160 requests the disk pool area allocation unit 140 to allocate a disk pool area. Then, the data area rearrangement unit 160 copies the original data to the allocated area and deletes the data area before copying, thereby making the discontinuous data area a continuous data area.

  In addition, in the case of a logical disk in which the allocation policy is set to emphasize capacity, the data area relocation unit 160 includes a releasable area in each data area allocated to each of a plurality of consecutive physical blocks. Determine if it exists. If a releasable area exists, the data area rearrangement unit 160 sets this as a disk pool area.

  Specifically, the data area rearrangement unit 160 determines physical block IDs in which data areas are continuously allocated in allocation units when speed is important when the allocation policy is set to focus on capacity. set to target. Then, the data area rearrangement unit 160 divides the data area to be determined by the allocation unit when the capacity is important, and determines whether there is a disk pool area that can be released in this case. If it exists, the data area rearrangement unit 160 releases the area and returns it to the disk pool 200, thereby making the area reusable.

  Next, the function of each unit of the storage apparatus 100 will be described in chronological order, focusing on the linkage of each unit. First, a virtual logical disk group 120 is constructed in the disk pool 200. In this case, the disk pool area allocation unit 140 of the storage apparatus 100 sets an allocation policy for each constructed virtual logical disk (120a to 120c).

  When data is written from the host computers 300, 310, and 320 to the new virtual logical disk group 120, the data writing unit 130 refers to the disk pool area management table 180 (see FIG. 3). Then, the data writing unit 130 determines whether there is a writable disk pool area.

  If there is no disk pool area for writing, the data writing unit 130 requests the disk pool area allocation unit 140 to allocate the disk pool area. Upon receiving the disk pool area allocation request, the disk pool area allocation unit 140 refers to the allocation policy management table 190 (see FIG. 4) and allocates the disk pool area for the allocation unit set in the allocation policy.

  When the disk pool area allocation is performed, the disk pool area allocation unit 140 updates the disk pool area management table 180 (see FIG. 3) and the logical disk area management table 170 (see FIG. 2). Then, the disk pool area allocation unit 140 notifies the data writing unit 130 that the disk pool area has been allocated.

  In response to securing the area from the disk pool area allocation unit 140, the data writing unit 130 writes data in the secured area. Then, the data writing unit 130 registers the characteristics including the I / O size of the written data and the I / O pattern (access method) in the I / O pattern integration table 210.

  Further, at the same time when the storage apparatus 100 performs the above-described operation, the allocation policy management unit 150 periodically monitors the I / O pattern integration table 210. The allocation policy management unit 150 uses the I / O pattern discrimination method including setting of the threshold value of the total number, and the preset allocation policy becomes inconsistent with the I / O pattern, and is further attributed to the I / O pattern. Then, it is determined whether or not the threshold value needs to be changed. If there is a need to change the threshold value, the allocation policy management unit 150 temporarily changes the allocation unit of the allocation policy management table 190.

  Furthermore, when the allocation unit is temporarily changed and the cumulative number falls below the threshold value, the allocation policy management unit 150 executes an operation for returning the allocation unit. Also, the allocation policy management unit 150 periodically resets the I / O pattern integration table 210.

  The data area rearrangement unit 160 operates periodically. In the data area relocation unit 160, the allocation policy of the logical disks (120a to 120c) is speed-oriented, and the physical block IDs of the logical disks (120a to 120c) are allocated discontinuously and can be made continuous. If there is, a continuous physical block is allocated to the data area and the data is rearranged.

  Further, the data area relocation unit 160 determines whether there is a physical block ID in which data areas are continuously allocated in allocation units when the priority is on speed when the allocation policy of the logical disk is priority on capacity. If it exists, the data area rearrangement unit 160 further determines whether or not there is a data area that can be released as a disk pool area when it is divided by the allocation unit when capacity is important. If the data area exists, the data area relocation unit 160 returns the data area to the original disk pool area, and the optimum disk pool operation can be performed.

  Next, an area allocation method according to the embodiment of the present invention will be described with reference to FIGS. The area allocation method in the present embodiment is implemented by operating the storage apparatus in the present embodiment shown in FIG. For this reason, the area allocation method in the present embodiment will be described together with the operation of the storage apparatus 100 while referring to FIGS. 1 to 6 as appropriate.

  FIG. 7 is a flowchart showing the operation of the data writing unit constituting the storage apparatus. FIG. 8 is a flowchart showing the operation of the disk pool area allocation unit constituting the storage apparatus. FIG. 9 is a flowchart showing the operation of the allocation policy management unit constituting the storage apparatus. FIG. 10 is a flowchart showing the operation of the data area rearrangement unit constituting the storage apparatus.

  First, processing performed by the data writing unit 130 will be described with reference to FIG. The data writing unit 130 operates when receiving a data write request from the host computers 300, 310, 320. Then, as shown in FIG. 7, the data writing unit 130 refers to the logical disk area management table 170 (S22), and whether or not there is a disk pool area for writing to the logical disk that has been requested to write data. Is confirmed (S24).

  In step S24, the data writing unit 130, which has determined that there is no data writing area, makes a disk pool area allocation request for writing data to the disk pool area allocation unit 140 (S26).

  Next, when the data writing unit 130 receives a notification from the disk pool area allocation unit 140 that a disk pool area for writing data is secured, the data writing unit 130 writes data to the logical disk. (S28)

  Thereafter, the data writing unit 130 that has completed the data writing adds the I / O characteristics of the written data to the I / O pattern integration table 210 (S30), and ends the process.

  Next, processing performed by the disk pool area allocation unit 140 will be described with reference to FIG. The disk pool area allocation unit 140 starts the operation when a disk pool area allocation request (S26) by the data writing unit 130 or a disk pool area allocation request by the data area rearrangement unit 160 described later is made.

  As shown in FIG. 8, first, when receiving a disk pool area allocation request, the disk pool area allocation unit 140 refers to the allocation policy management table 190 (S42). Next, the disk pool area allocation unit 140 allocates a disk pool area to this according to the allocation policy set for the requested logical disk (S44).

  Next, the allocated disk pool area allocation unit 140 updates the logical disk area management table 170 (see FIG. 2) and the disk pool area management table 180 (see FIG. 3) (S46). Then, the disk pool area allocation unit 140 ends the process.

  Next, processing performed by the allocation policy management unit 150 will be described with reference to FIG. The allocation policy management unit 150 operates in response to a request from a user or periodically.

  As shown in FIG. 9, first, the allocation policy management unit 150 refers to the I / O pattern integration table 210 (see FIG. 6) and the allocation policy management table 190 (see FIG. 4) (S62). Next, the allocation policy management unit 150 checks whether there is a logical disk exceeding the threshold set in the I / O pattern integration table 210 (S64).

  When there is a logical disk exceeding the threshold set in the I / O pattern integration table 210, the allocation policy management unit 150 changes the allocation unit (S66) and updates the allocation policy management table 190 (S68).

  Next, processing performed by the data area rearrangement unit 160 will be described with reference to FIG. The data area rearrangement unit 160 operates in response to a request from a user or periodically. As shown in FIG. 10, first, the data area relocation unit 160 refers to the logical disk area management table 170 (see FIG. 2) and the allocation policy management table 190 (see FIG. 4) (S82). Next, the data area rearrangement unit 160 determines whether the allocation policy is speed-oriented or capacity-oriented for each logical disk (S84).

  If the logical disk allocation policy is set to emphasize speed in step S84, the data area relocation unit 160 allocates non-contiguous physical blocks in the logical disk to the allocation unit set to the speed-oriented allocation policy. (S86).

  If it does not exist in step S86, the data area rearrangement unit 160 determines that there is no area that can be rearranged, stops the operation, and ends the process. On the other hand, if it exists in step S86, the data area rearrangement unit 160 determines that the discontinuous physical blocks can be made continuous, and requests the disk pool area allocation unit 140 to allocate a disk pool area. (S88).

  Then, the data area rearrangement unit 160 rearranges the data from the discontinuous physical block to the continuous physical block by copying the data to the allocated area (S90). After completion of the relocation in step S90, the data area relocation unit 160 releases the data area before relocation and returns it to the disk pool area (S92). Then, the data area relocation unit 160 updates the logical disk area management table 170 (S94) and ends the process.

  If the logical disk allocation policy is set to emphasize capacity in step S84, the data area relocation unit 160 checks whether there is a releasable area in the continuously secured physical blocks. (S96). Specifically, the data area rearrangement unit 160 checks whether there is an area that can be released when a continuous physical block is divided into allocation units set in a capacity-oriented allocation policy.

  If there is a releasable physical block in step S96, the data area relocation unit 160 releases the releasable physical block, returns it to the disk pool area (S98), and updates the logical disk area management table 170 ( S100). On the other hand, if there is no area that can be released in step S96, the data area rearrangement unit 160 stops the operation and ends the process.

  Further, the program in the present embodiment executes steps S22 to S30 shown in FIG. 7, steps S42 to S46 shown in FIG. 8, steps S62 to S68 shown in FIG. 9, and steps S82 to S100 shown in FIG. Any program can be used. When this program is installed in a computer and executed, the computer functions as the storage apparatus 100. In this case, a central processing unit (CPU) of the computer functions as a data writing unit 130, a disk pool area allocation unit 140, an allocation policy management unit 150, and a data area rearrangement unit 160, and performs processing.

  Furthermore, in this embodiment, the logical disk area management table 170, the disk pool area management table 180, the allocation policy management table 190, the I / O pattern integration table 210, and the allocation policy setting table 220 are the hard disks provided in the computer. This can be realized by storing data files constituting these in a storage device such as the above. These tables can also be realized by mounting a recording medium in which a data file is stored in a reading device connected to a computer.

  As described above, according to the present embodiment, the following effects can be obtained. First, in this embodiment, even when there are different I / O patterns for one logical disk, the allocation size of the area of the disk pool is allocated according to the allocation policy set for the logical disk. Therefore, according to the present embodiment, an area of a large allocation unit can be allocated to a logical disk with a large number of sequential I / Os, so that fragmentation of the area is suppressed and the response of sequential I / O is suppressed. Degradation is reduced.

  That is, the storage apparatus 100 according to the present embodiment can determine the I / O pattern (for example, sequential I / O and random I / O) along with the I / O size at the time of data writing. This is because, by setting the allocation policy for the logical disk, the sequential I / O can be allocated in units of allocation according to the allocation policy.

  Further, according to the present embodiment, the capacity efficiency can be improved by selecting the allocation size of the disk pool area according to the allocation policy set for the logical disk. In other words, if an allocation policy for capacity priority or speed priority is set for each logical disk and capacity is prioritized, even if the I / O size is large, the data area is allocated with a small size, and unnecessary allocation is performed. This is because is not done.

  Furthermore, in this embodiment, since the allocation policy set for the logical disk is switched according to the I / O size and I / O pattern of data written to the logical disk, management when setting the allocation unit for each logical disk Cost is reduced.

  In this embodiment, when a discontinuous physical block is allocated to a logical disk set to emphasize speed, a data area is rearranged in a continuous physical block and a sequential I / O is performed. It is possible to reduce the deterioration of the response.

  Furthermore, according to the present embodiment, when a continuous large allocation unit is allocated to a logical disk whose allocation policy is set to emphasize capacity, a physical block can be divided into allocation units that emphasize capacity. . As a result, if there is an unused area, the area can be released and returned to the disk pool, so that the capacity efficiency can be improved.

  As described above, the present invention can be applied to a storage apparatus and a storage system using the storage apparatus, and has industrial applicability.

FIG. 1 is a block diagram showing a configuration of a storage apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the logical disk area management table shown in FIG. FIG. 3 is a diagram showing an example of the disk pool area management table shown in FIG. FIG. 4 is a diagram showing an example of the allocation policy management table shown in FIG. FIG. 5 is a diagram showing an example of the allocation policy setting table shown in FIG. FIG. 6 is a diagram showing an example of the I / O pattern integration table shown in FIG. FIG. 7 is a flowchart showing the operation of the data writing unit constituting the storage apparatus. FIG. 8 is a flowchart showing the operation of the disk pool area allocation unit constituting the storage apparatus. FIG. 9 is a flowchart showing the operation of the allocation policy management unit constituting the storage apparatus. FIG. 10 is a flowchart showing the operation of the data area rearrangement unit constituting the storage apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Storage apparatus 110 Physical disk group 120 Logical disk group 120a, 120b, 120c Logical disk 130 Data writing part 140 Disk pool area allocation part 150 Allocation policy management part 160 Data area rearrangement part 170 Logical disk area management table 180 Disk pool area management Table 190 Allocation policy management unit 200 Disk pool 210 I / O pattern integration table 220 Allocation policy setting table 300, 310, 320 Host computer

Claims (15)

A storage device for constructing a virtual logical disk in a disk pool formed by physical disk groups,
In response to a data write request from an external host computer, a data area for writing the data is secured in the disk pool, the data is written, and the I / O pattern of the data is determined. , Data writing part,
When the data writing unit requests allocation of a disk pool area when the data writing unit secures the data area, it is used as the data area according to the allocation policy set in the logical disk. A disk pool area allocation unit for allocating the disk pool area;
A storage apparatus comprising: an allocation policy management unit that changes an allocation policy set in the logical disk in accordance with the I / O pattern determined by the data writing unit. As the allocation policy, a first policy or a second policy in which the size of the disk pool area that can be allocated at one allocation is different is set,
The disk pool area that can be allocated at one time allocation in the first policy is set larger than the disk pool area that can be allocated at one time allocation in the second policy. The storage device described. Each time the I / O pattern is determined, the data writing unit accumulates the determined number of I / O patterns for each type,
The allocation policy management unit compares the number accumulated for each type of the I / O pattern with a set threshold, and changes the allocation policy set for the logical disk based on the comparison result. The storage apparatus according to claim 1 or 2. A plurality of the logical disks are constructed, and the physical disk has a plurality of physical blocks,
The storage apparatus further includes a data area rearrangement unit that rearranges the data area using the disk pool area,
The data area rearrangement unit has a plurality of data areas allocated to a plurality of non-consecutive physical blocks for a logical disk in which the first policy is set. The storage apparatus according to any one of claims 1 to 3, wherein the plurality of data areas are rearranged so as to be allocated to each block.   For the logical disk to which the second policy is set, the data area relocation unit includes a releasable area in each data area allocated to each of a plurality of consecutive physical blocks. The storage apparatus according to claim 4, wherein it is determined whether or not there is a releasable area, and this is used as a disk pool area. An area allocation method for allocating a disk pool area when constructing a virtual logical disk in a disk pool formed of physical disk groups,
(A) in response to a data write request from an external host computer, securing a data area for writing the data in the disk pool, and writing the data;
(B) determining an I / O pattern of the data; and
(C) When allocation of a disk pool area becomes necessary when the data area is secured in the step (a), it is used as the data area according to an allocation policy set for the logical disk. Allocating the disk pool area
(D) changing the allocation policy set in the logical disk in accordance with the I / O pattern determined in the step (a). As the allocation policy, a first policy or a second policy in which the size of the disk pool area that can be allocated at one allocation is different is set,
The disk pool area that can be allocated at one time allocation in the first policy is set larger than the disk pool area that can be allocated at one time allocation in the second policy. The area allocation method described. (E) The step of integrating the number of the determined I / O patterns for each type for each determination in the step (a) is further provided,
In the step (b), the number of I / O patterns accumulated for each type in the step (e) is compared with a set threshold value, and the logical disk is determined based on the comparison result. The area allocation method according to claim 6 or 7, wherein a set allocation policy is changed. A plurality of the logical disks are constructed, and the physical disk has a plurality of physical blocks,
(F) further comprising the step of rearranging the data area using the disk pool area;
In the step (f), for the logical disk for which the first policy is set, a plurality of data areas allocated to each of a plurality of non-consecutive physical blocks include a plurality of continuous physical The area allocation method according to claim 6, wherein the plurality of data areas are rearranged so as to be allocated to each block.   In the step (f), for the logical disk to which the second policy is set, a releasable area is included in each data area allocated to each of a plurality of consecutive physical blocks. 10. The area allocation method according to claim 9, wherein it is determined whether or not there is a releasable area, and this area is used as a disk pool area. A program for causing a computer to execute allocation of a disk pool area when constructing a virtual logical disk in a disk pool formed by a group of physical disks,
In the computer,
(A) in response to a data write request from an external host computer, securing a data area for writing the data in the disk pool, and writing the data;
(B) determining an I / O pattern of the data; and
(C) When allocation of a disk pool area becomes necessary when the data area is secured in the step (a), it is used as the data area according to an allocation policy set for the logical disk. Allocating the disk pool area
(D) executing a step of changing an allocation policy set in the logical disk in accordance with the I / O pattern determined in the step (a). As the allocation policy, a first policy or a second policy in which the size of the disk pool area that can be allocated at one allocation is different is set,
The disk pool area that can be allocated at one time allocation in the first policy is set to be larger than the disk pool area that can be allocated at one time allocation in the second policy. The listed program. (E) causing the computer to further execute a step of accumulating the number of discriminated I / O patterns for each type for each discrimination in the step of (a),
In the step (b), the number of I / O patterns accumulated for each type in the step (e) is compared with a set threshold value, and the logical disk is determined based on the comparison result. The program according to claim 11 or 12, which changes a set allocation policy. A plurality of the logical disks are constructed, and the physical disk has a plurality of physical blocks,
(F) causing the computer to further execute the step of rearranging the data area using the disk pool area;
In the step (f), for the logical disk for which the first policy is set, a plurality of data areas allocated to each of a plurality of non-consecutive physical blocks include a plurality of continuous physical The program according to any one of claims 11 to 13, wherein the plurality of data areas are rearranged so as to be allocated to each block.   In the step (f), for the logical disk to which the second policy is set, a releasable area is included in each data area allocated to each of a plurality of consecutive physical blocks. The program according to claim 14, wherein it is determined whether or not there is a releasable area, and this is set as a disk pool area.

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