JP2019148977A - Disk array apparatus and disk pool capacity expanding method - Google Patents

Abstract

To provide a disk array apparatus capable of avoiding a business work suspension caused by the insufficiency in capacity of a disk pool.SOLUTION: A disk array apparatus includes: a disk pool monitoring unit 121 that monitors whether or not the use capacity of a disk pool which collectively manages the capacities of respective physical disks forming one or a plurality of RAIDs reaches a predefined capacity threshold; an available region managing unit 122 that secures and manages the available region in each of the physical disks as a capacity for expanding the disk pool in the case of emergency with a difference in capacity among the plurality of physical disks forming each RAID being taken into consideration; and an emergency capacity securing unit 123 which determines that, on the basis of the monitoring result by the disk pool monitoring unit 121, when the use capacity of the disk pool reaches the threshold, an emergency expansion status occurs, and which tentatively allocates the available region secured by the available region managing unit 122 as a volume for capacity expansion of the disk pool.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a disk array device and a disk pool capacity expansion method, and more particularly to a disk array device and a disk pool capacity expansion method that perform capacity expansion when a disk pool capacity is insufficient in a disk array apparatus that provides a virtual volume.

  A disk array device is configured with a controller that controls a number of physical disks and is configured with RAID (Redundant Arrays of Independent Disks) to improve reliability and performance. A logical volume is provided to an external device such as a server.

  In a disk array device, a volume can be efficiently used by a thin provisioning technology. In a disk array device to which the thin provisioning technology is applied, one or more existing RAID-configured volumes can be collected in a disk pool. In such a disk array device, it is possible to set the total capacity of logical volumes provided to external devices such as servers to a capacity larger than the actual capacity of the disk pool by collecting RAID-configured volumes in a disk pool. As a virtual volume, it can be assigned to an external device such as a server. By employing virtual volumes, one or more virtual volumes can be assigned to one server, or one or more virtual volumes can be assigned to a plurality of other servers.

  Since the actual used capacity of the virtual volume is small at the initial stage of installation, the total used capacity is within the actual capacity of the disk pool even if the used capacity varies for each virtual volume according to the usage status. The disk can be allocated and used efficiently. However, if the total capacity used by the virtual volume exceeds the actual capacity of the disk pool and the capacity of the disk pool is insufficient, writing in an external device such as a server will fail, and continuation of operations that use the virtual volume will continue. Becomes difficult. For this reason, in order to prevent the disk pool from having insufficient capacity, it is necessary to expand the disk pool by systematically adding physical disks.

  As an example of a technique for preventing a disk pool capacity shortage, for example, Japanese Patent Laid-Open No. 2007-193573, “Storage device system and storage control method” of Patent Document 1, is disclosed. This patent document 1 proposes a method of eliminating a disk pool capacity shortage by transferring a virtual volume having a plurality of disk pools and causing a shortage of capacity to another disk pool.

  For physical disks, there is a difference in the actual usable capacity even if the same capacity is indicated due to differences in products such as vendors. It is used with a capacity that takes into account the capacity on the disk side. When configuring the RAID, from the viewpoint of setting the actually usable capacity to the same, the physical that is the same production, the same vendor, the same model number, and the same firmware version Although the use of disks seems desirable, there is also the idea that it is better not to have the same physical disks in consideration of the physical disk production lot defect.

  In addition, in a RAID configuration, since a failed physical disk is replaced, it may be difficult to prepare all the same physical disks that are RAID configured at the time of introduction as physical disks for repair parts. Therefore, in the RAID configuration, the capacity may be set to be smaller than the capacity of the physical disk in consideration of causing a capacity difference.

  Further, when a plurality of RAIDs are configured, there may be a case where physical disks having different capacities in RAID units are used. For example, there is a mixture of a RAID configuration composed of physical disks with 1 TB notation and a RAID configuration composed of physical disks with 2 TB notation. In such a configuration, when a physical disk configured as RAID fails, a hot spare disk that is a spare physical disk is incorporated into the RAID configuration instead of the failed physical disk. At this time, since a physical disk constituting a RAID can use a large capacity disk instead of a small capacity disk, the hot spare disk may be composed of a large capacity physical disk. For example, in the case of a mixed RAID configuration of 1 TB and 2 TB, a hot spare disk may be configured using a 2 TB disk.

JP 2007-193573 A

  In the current technology as described above, the following problems cannot be solved. In other words, when assigning more than the actual capacity of the virtual volume to be allocated to the server, etc., with the thin provisioning function in the disk array device, plan and monitor the capacity in advance so that the capacity of the disk pool will not be insufficient. It is necessary to add a new physical disk and expand the disk pool.

  Here, there are the following points as problems in such a case. That is, at the time of initial installation, in order to reduce the budget and the like, the introduction of a virtual volume configured by a disk array device having a minimum physical capacity is increasing. Therefore, in order to continue using the virtual volume, it is premised that the addition of the physical disk and the expansion of the disk pool are periodically performed. However, if the virtual volume usage capacity suddenly exceeds the assumption, the addition of the physical disk may not be in time, including preparations such as budget and arrangement. In such a case, a situation in which writing to the virtual volume cannot be performed due to insufficient capacity of the disk pool occurs, and the server side business cannot be continued. Further, depending on the type of OS (Operating System) and software on the server side, a failure may occur, which may cause a significant hindrance to business continuity.

  In addition, even in the technique of efficiently accommodating capacity between a plurality of disk pools as in Patent Document 1, in the configuration at the time of introduction where there is no room for capacity as a whole, sudden increase in capacity is prevented. The capacity that can expand the capacity of the disk pool is also limited. Therefore, it is impossible to cope with the situation, and writing cannot be performed due to the lack of capacity of the disk pool or the disk pool, and the server side business cannot be continued. Similarly, depending on the type of OS or software on the server side, a failure may occur, resulting in a significant hindrance to business continuity.

  That is, in the disk array device of the current technology related to the present invention including the technology described in Patent Document 1, the disk pool capacity is insufficient, and the disk writing cannot be performed on the external device side such as a server. It will not be possible to prevent the occurrence of a situation where the business is stopped. Furthermore, depending on the type of OS and software on the server side, a failure may occur, resulting in a significant hindrance to business continuity. Thus, the current technology related to the present invention has a problem to be solved.

(Object of the present invention)
In view of the above-described problems, an object of the present disclosure is to provide a disk array device and a disk pool capacity expansion method capable of avoiding a business stop caused by a disk pool capacity shortage.

  In order to solve the above-mentioned problems, the disk array device and the disk pool capacity expansion method according to the present invention mainly adopt the following characteristic configuration.

(1) A disk array device according to the present invention includes:
Providing a virtual volume by forming a disk pool that collectively manages the capacity of each physical disk constituting one or more RAIDs;
Disk pool monitoring means for monitoring whether the used capacity of the disk pool has reached a threshold;
Unused area management means for securing and managing an unused area generated in each of the physical disks as a capacity for expanding an emergency disk pool;
And an emergency capacity securing unit that temporarily allocates the unused area as a capacity expansion volume of the disk pool when the used capacity of the disk pool reaches the threshold based on the monitoring result. And

(2) A disk pool capacity expansion method according to the present invention includes:
Extending the capacity of the disk pool of a disk array device that provides a virtual volume by forming a disk pool that collectively manages the capacity of each physical disk constituting one or more RAIDs;
A disk pool monitoring step for monitoring whether the used capacity of the disk pool has reached a threshold;
An unused area management step for securing and managing an unused area generated in each of the physical disks as a capacity for expanding an emergency disk pool;
An emergency capacity securing step for temporarily allocating the unused area as a capacity expansion volume of the disk pool when the used capacity of the disk pool reaches the threshold based on the monitoring result. It is characterized by that.

  According to the disk array device and the disk pool capacity expansion method of the present invention, the following effects can be mainly achieved.

  In other words, in the present invention, it is possible to avoid a business stop caused by a lack of disk pool capacity and to continue the business. The reason for this is that by using the capacity of the unused area that occurs in consideration of the capacity difference in the physical disks that form the RAID configuration, the disk pool can be temporarily expanded in an emergency to reduce the capacity shortage. This is because it is possible to avoid it.

1 is a system configuration diagram showing an example of a system configuration of a disk array device according to the present invention. FIG. 2 is a configuration diagram for explaining a configuration of a disk pool of the disk array device shown in FIG. 1. 3 is a flowchart illustrating an example of a disk pool capacity expansion operation that is performed in an emergency in the disk array device illustrated in FIG. 1. 3 is a flowchart for explaining an example of an operation of returning from the emergency expansion state by the capacity expansion of the emergency disk pool using an unused area to return to the normal state in the disk array device shown in FIG. 1.

  Preferred embodiments of a disk array device and a disk pool capacity expansion method according to the present invention will be described below with reference to the accompanying drawings. It should be noted that the reference numerals attached to the following drawings are added for convenience to each element as an example for facilitating understanding, and it is needless to say that the present invention is not intended to be limited to the illustrated embodiment. Yes.

(Features of the present invention)
Prior to the description of the embodiments of the present invention, an outline of the features of the present invention will be described first. The disk array device of the present invention provides a virtual volume by forming a disk pool that collectively manages the capacities of physical disks constituting one or more RAIDs. This disk array device comprises a disk pool monitoring means for monitoring whether or not the used capacity of the disk pool has reached a threshold value, and an unused area generated in each physical disk for expanding an emergency disk pool Unused area management means for securing and managing the capacity as a storage capacity. Further, based on the monitoring result, when the used capacity of the disk pool reaches the threshold, it is determined that an emergency expansion state has occurred, and the unused area is used as a capacity expansion volume of the disk pool. The main feature is that it further has an emergency capacity securing means to be temporarily allocated. The main feature is that the disk array device can be configured as a logical volume and a disk array device having a thin provisioning function capable of allocating a virtual volume larger than the actual capacity to an external device such as a server. One.

(Configuration example of embodiment of the present invention)
Next, a configuration example of an embodiment of a disk array device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a system configuration diagram showing an example of the system configuration of a disk array device according to the present invention. In addition to the internal configuration of the disk array device, an example of a device connected to the disk array device is also shown. .

  As shown in FIG. 1, a disk array device 10 showing an example of the present invention includes a server group such as a server 21, a server 22,... That is an external device to which a virtual volume is provided from the disk array device 10, and the disk A management terminal 30 that manages the array device 10 and performs setting and status monitoring is connected.

  Further, inside the disk array device 10, a control unit 100 that controls the operation of the disk array device 10, a plurality of physical disks 210 to 214,..., A plurality of physical disks 220 installed in the disk array device 10. 224, and a disk unit 200 in which a large number of physical disks such as a plurality of physical disks 230 and 231 are grouped. As shown in FIG. 1, the capacity of each of the physical disks 210 to 213, the physical disk 214 and the physical disks 220 to 224, and the physical disks 230 and 231 is, for example, 1 TB, 2 TB, and 2 TB.

  Further, the control unit 100 performs setting operation processing for assigning the physical disks 210 to 214,..., The physical disks 220 to 224, and the physical disks 230 and 231 as RAID 311,. As a process of the virtual volume function of the unit 100, it is possible to logically control by forming a disk pool 300 in which the capacity of the RAID configuration is collected. It is also possible to add a thin provisioning function that can allocate a virtual volume to an external device such as the servers 21 and 22 as a capacity larger than the actual capacity of the disk pool 300.

  The server group such as the server 21, the server 22,... Shown in FIG. 1 performs data writing and data reading with respect to the disk array device 10, and FIG. However, one or more arbitrary number of servers may be connected. Further, as described above, the management terminal 30 shown in FIG. 1 receives various status information of the disk array device 10 and sets the disk array device 10. You may comprise so that the function of the management terminal 30 may be shared.

  As described above, the disk array device 10 includes the control unit 100 and the disk unit 200 including a large number of physical disks. As shown in FIG. 1, the control unit 100 includes a host management unit 111, a RAID / hot spare management unit 112, a disk pool management unit 113, a disk pool expansion unit 114, a physical disk management unit 115, a disk pool monitoring unit 121, an unused The area management unit 122, the emergency capacity securing unit 123, and the emergency state return unit 124 are included at least.

  Further, as described above, the disk unit 200 includes the RAID 311 configured by the plurality of physical disks 210 to 214, the RAID 312 configured by the plurality of physical disks 220 to 224, and the hot spare configured by the plurality of physical disks 230 and 231. 320, and further includes a disk pool 300 composed of RAID 311 and RAID 312.

  The control unit 100 uses the host management unit 111 to perform a process of providing a virtual volume capacity with the server group of the server 21, the server 22, and so on. One virtual volume may allocate one or more virtual volume capacities to one server, for example, server 21, and one virtual volume is allocated to one or more servers, such as server 21 and server 22. The above virtual volume capacity may be allocated.

  Further, the control unit 100 uses the physical disk management unit 115 to perform connection processing among the plurality of physical disks 210 to 214, the plurality of physical disks 220 to 224, and the plurality of physical disks 230 and 231 of the disk unit 200. Yes.

  Also, the control unit 100 uses the RAID / hot spare management unit 112 to create a RAID 311 RAID configuration including a plurality of physical disks 210 to 214 in the disk unit 200 and a RAID 312 RAID configuration including a plurality of physical disks 220 to 224. A process for forming the hot spare 320 is performed, and a process for configuring the hot spare 320 by the plurality of physical disks 230 and 231 is performed.

  Further, the control unit 100 performs processing of the virtual volume function (including the thin provisioning function) by the disk pool management unit 113, and summarizes the physical capacities of the two RAID configurations of the RAID 311 and the RAID 312 of the disk unit 200. Processing to configure the disk pool 300 is performed. In FIG. 1, the two RAID configurations of RAID 311 and RAID 312 are combined into one disk pool, but one disk pool may be configured with one or more arbitrary RAID configurations. A plurality of disk pools may be configured.

  In addition, the control unit 100 uses the disk pool expansion unit 114 to perform expansion processing for adding capacity to the disk pool 300.

  Further, the control unit 100 uses the disk pool monitoring unit 121 to monitor the threshold regarding the capacity of the disk pool 300, and assigns the total physical disk capacity of the disk pool 300 and the servers (server group of the server 21, server 22,...). The usage rate of the total capacity actually used in the virtual volume is monitored.

  The control unit 100 also uses the unused area management unit 122 to create a RAID configuration that takes into account the capacity difference between the physical disks (a plurality of physical disks 210 to 214 and a plurality of physical disks 220 to 224) configured in RAID. The unused area that is not used by the system is secured and managed. Details of the unused area will be described later in the description of the RAID configuration of the disk pool 300 in FIG.

  In addition, the control unit 100 uses the emergency capacity securing unit 123 to secure the unused areas managed by the unused area management unit 122 together and temporarily allocate the capacity as a capacity expansion volume of the disk pool 300. I do.

  In addition, after expanding the capacity of the disk pool 300 by adding a physical disk, the control unit 100 expands the capacity of the disk pool 300 from the unused area to the data written in the unused area by the emergency state return unit 124. Move to the volume (added physical disk) and return to the original unused area.

  The disk unit 200 is connected to a plurality of physical disks 210 to 214, a plurality of physical disks 220 to 224, and a plurality of physical disks 230 and 231, respectively, and is configured by a RAID configuration of RAID 311 and RAID 312 and a hot spare 320. . FIG. 1 shows an example of a hot spare configuration composed of two RAID configurations and two physical disks, but it may be a configuration of one or more RAID configurations and zero or more hot spares.

  FIG. 1 shows an example in which RAID 311 and RAID 312 have a RAID configuration composed of five physical disks 210 to 214 and five physical disks 220 to 224, respectively. A RAID configuration composed of an arbitrary number of physical disks may be used. Of the five physical disks 210 to 214 constituting the RAID 311, the capacity of the four physical disks 210 to 213 is 1 TB, but only the capacity of the physical disk 214 is accidentally changed to 2 TB as the result of the physical disk repair and replacement. In this case, the capacity of the physical disks 210 to 213 is different.

  Further, the disk unit 200 forms a disk pool 300 in which the physical capacities of the two RAID configurations of RAID 311 and RAID 312 are combined. In FIG. 1, two RAID configurations are combined into one disk pool 300, but one disk pool may be configured with one or more RAID configurations, and one RAID configuration may be one with one or more RAID configurations. It may be configured by two or more disk pools.

  Next, the disk pool 300 of the disk array device 10 shown in FIG. 1 will be further described with reference to FIG. FIG. 2 is a configuration diagram for explaining the configuration of the disk pool 300 of the disk array device 10 shown in FIG. As shown in FIG. 1, the disk pool 300 in FIG. 2 is configured with RAID 311 and RAID 312, but each of the physical disks 210 to 214 configured as RAID 311 and each of the physical disks configured as RAID 312. Considering the capacity difference between 220 to 224, an example in which an unused area exists for each of them is also shown.

  That is, the RAID 311 has a RAID configuration including five physical disks: a physical disk 210, a physical disk 211, a physical disk 212, a physical disk 213, and a physical disk 214. Here, the physical disk 210 and the physical disk 211 are physical disks expressed as 1 TB capacity, and the physical disk 212 and the physical disk 213 are similarly physical disks expressed as 1 TB capacity. These two physical disks 210 and 211 and the latter two physical disks 212 and 213 are physical disks with different vendors and model numbers, and show an example in which there is a slight capacity difference. The physical disk 214 is a physical disk expressed as 2 TB capacity.

  In the RAID configuration configured by a plurality of physical disks having different capacity differences, the RAID capacity is set in accordance with the physical disk having the smaller capacity. Therefore, in the case of RAID 311, it is not used for the RAID configuration. An area 401 exists. That is, in the example shown in FIG. 2, since the capacity of the physical disks 210 and 211 is the smallest, an example in which the unused area 401 exists in the physical disks 212, 213, and 214 is shown.

  The RAID 312 has a RAID configuration including five physical disks: a physical disk 220, a physical disk 221, a physical disk 222, a physical disk 223, and a physical disk 224. Here, the physical disk 220, the physical disk 221, and the physical disk 222 are physical disks expressed as 2TB capacity, and the physical disk 223 and the physical disk 224 are also physical disks expressed as 2TB capacity. The former three physical disks 220 to 222 and the latter two physical disks 223 and 224 are physical disks of different vendors and model numbers, and show an example in which a slight capacity difference occurs.

  As described above, in the RAID configuration configured by a plurality of physical disks having different capacity differences, the capacity of the RAID is set in accordance with the physical disk having the smaller capacity. Further, the physical disk to be replaced in the future. In the case of RAID 312, the used capacity in the RAID configuration is set to be small, and there is an unused area 402 that is not used in the RAID configuration. That is, in the example illustrated in FIG. 2, an example in which the unused area 402 exists in all of the physical disks 220 to 224 is illustrated.

  In the present embodiment, an unused area generated in consideration of a capacity difference between physical disks in a RAID configuration, such as an unused area 401 in RAID 311 and an unused area 402 in RAID 312, in the present embodiment. Are temporarily allocated as a disk pool expansion area in an emergency.

(Description of the operation of the embodiment of the present invention)
Next, an example of the operation of the disk array device shown in FIGS. 1 and 2 as an embodiment according to the present invention will be described in detail. First, an example of the operation when the disk array device 10 shown in FIG. 1 expands the disk pool 300 temporarily in an emergency will be described in detail with reference to the flowchart of FIG. FIG. 3 is a flowchart for explaining an example of the capacity expansion operation of the disk pool 300 performed in the emergency in the disk array device 10 shown in FIG.

  In the control unit 100 of the disk array device 10 in FIG. 1, the disk pool monitoring unit 121 monitors the usage amount of the disk pool 300, sets a threshold value, and determines whether or not the usage amount exceeds the threshold value. The process is always performed in the background. In the flowchart of FIG. 3, first, the usage amount of the disk pool 300 is monitored by acquiring processing information of the virtual volume function (in some cases, a thin provisioning function in some cases) from the disk pool management unit 113. Usage rate based on the total capacity of physical disks 210 to 214 and 220 to 224 (total capacity excluding unused areas 401 and 402) and the total capacity actually used as virtual volumes allocated to servers 21 and 22 And the monitoring is performed using the usage rate (step a001). Then, as discrimination monitoring, it is monitored whether or not the usage rate has reached a threshold set in advance as a capacity threshold.

  As a result of discrimination monitoring by the disk pool monitoring unit 121, it is determined whether the usage rate has reached the threshold (step a0002). If the usage threshold is exceeded (YES in step a0002), the disk pool 300 is configured. The process proceeds to the confirmation step of unused areas 401 and 402 in the RAID 311 and RAID 312 (step a003). On the other hand, if the threshold is not exceeded (NO in step a0002), the process returns to step a001 to use the disk pool 300. Continue volume monitoring.

  In step a003, the control unit 100 of the disk array device 10 causes the unused area management unit 122 to use an unused area that is not used in the RAID configuration among the plurality of physical disks 210 to 214 and the physical disks 220 to 224. 401 and 402 are searched for, and a preparation process for use as a volume for expanding the capacity of the disk pool 300 is performed (step a003).

  Thereafter, the emergency capacity securing unit 123 secures a capacity that can be used as a capacity expansion volume of the disk pool 300 for the unused areas 401 and 402 prepared in the unused area management unit 122. (Step a004).

  Then, the emergency capacity securing unit 123 performs a process of additionally expanding the volume set from the actual usage amount area to the disk pool 300 via the disk pool expansion unit 114 (step a005). By this processing, the capacity of the disk pool 300 is expanded, and it is possible to avoid a business stop due to a lack of capacity of the disk pool 300.

  Thereafter, the control unit 100 of the disk array device 10 sets the status where the emergency capacity securing unit 123 has expanded the capacity of the disk pool 300 using the unused areas 401 and 402 as the status of the disk array device 10. To the external device that uses the disk pool 300 of the disk array device 10 such as the management terminal 30 and the servers 21 and 22 that manage the disk array device 10 as a virtual volume. Status information indicating the occurrence is notified (step a005). As for the status information, when the status confirmation is transmitted from the management terminal 30 or the servers 21 and 22 to the disk array device 10, the status information indicating the emergency extended state is notified. Also good.

  Next, the status of the disk array device 10 shown in FIG. 1 is released from the emergency expansion state in which the capacity of the disk pool 300 is expanded using the unused areas 401 and 402 in an emergency by the operation of the flowchart of FIG. An example of the operation when returning to the state will be described in detail with reference to the flowchart of FIG. FIG. 4 shows an example of an operation for returning from the emergency expansion state due to the capacity expansion of the emergency disk pool 300 using the unused areas 401 and 402 to return to the normal state in the disk array device 10 shown in FIG. It is a flowchart to explain. That is, in the flowchart of FIG. 4, after a physical disk is newly added and the disk pool 300 is expanded, the volume temporarily used in an emergency is returned to the original unused areas 401 and 402. An example of the operation until returning to the normal state is described so that it is possible to cope with the emergency extension state that may occur next.

  In the flowchart of FIG. 4, first, when a physical disk is newly added to the disk array device 10 of FIG. 1, the control unit 100 of the disk array device 10 of FIG. After the process of connecting and recognizing the disk, the RAID / hot spare management unit 112 performs the process of setting the RAID configuration of the newly added physical disk, and the disk pool 300 is expanded. (Step b001).

  Next, the control unit 100 of the disk array device 10 uses the disk pool expansion unit 114 to check the current status of the disk array device 10 and determine whether there is an emergency expansion state (step b002). If the current status of the disk array device 10 is not the emergency expansion state (NO in step b002), the process proceeds to step b006, and the disk pool expansion is normally completed.

  On the other hand, if the current status of the disk array device 10 is the emergency extended state (YES in step b002), the process proceeds to step b003, and temporarily as an emergency by the operation shown in the flowchart of FIG. Perform processing to restore the expanded volume to its original state. That is, the emergency state return unit 124 expands the write data, which was created in the flowchart of FIG. 3 as the emergency extension process in the flowchart of FIG. 3 (the emergency extension area in the RAID), by newly adding a physical disk. After moving to the new area of the disk pool 300 (step b003), the process proceeds to the process after step b004, and the process proceeds to the process of returning the volume created as the emergency expansion process to the unused areas 401 and 402.

  First, in step b004, the emergency state return unit 124 deletes the write data that has been created for the volume (emergency expansion area in the RAID) created in the flowchart of FIG. The volume (emergency expansion area in RAID) is released and returned to the original unused areas 401 and 402 (step b004).

  Thereafter, in step b005, the emergency state return unit 124 returns the status of the disk array device 10 from the emergency extended state to the normal state, and further manages the disk array device 10 and the management terminal 30 and the server 21. Status information indicating that the status of the disk array device 10 has returned from the emergency extended state to the normal state with respect to an external device that uses the disk pool 300 of the disk array device 10 as a virtual volume. Is notified (step b005). As for the status information, when the status confirmation is transmitted from the management terminal 30 or the servers 21 and 22 to the disk array device 10, the status information indicating the normal state is notified. Also good.

  As described above, when the disk pool expansion process is completed (step b006), the disk array apparatus 10 is returned to a normal state and the capacity of the next disk pool 300 is insufficient. In an emergency, the disk pool 300 can be expanded using the unused areas 401 and 402.

  In addition, as an example of a physical disk having a capacity difference in a RAID configuration physical disk, as described above, even if the physical disk has the same capacity notation, the capacity difference due to the vendor is different. Even with the same vendor, there is a difference in capacity due to the difference in the density of internal components in the physical disk and the difference in firmware at the time of release. In other words, there is actually a difference in capacity even if the same capacity is indicated. In addition, since the RAID configuration replaces a failed physical disk, it may be difficult to prepare all the same physical disks that are RAID configured at the time of introduction as the physical disks for repair parts.

  Therefore, it is necessary to consider that a capacity difference occurs in the RAID configuration. Therefore, the unused areas 401 and 402 set in the physical disk in the capacity setting of the RAID configuration as shown in FIG. 2 are not only the differences in the physical disk vendor, model number, firmware version, etc., but also later. Considering the physical disk for repair used at the time of failure, it is necessary to include the case where the capacity used in the RAID configuration is set smaller than the actual capacity of the physical disk.

  As shown in FIG. 1, as the physical disks 230 and 231 of the hot spare 320, physical disks having a capacity equal to or larger than that of the physical disks 210 to 214 and the physical disks 220 to 224 having a RAID configuration are used. Therefore, as an example of a disk having a capacity difference in a physical disk with a RAID configuration, a failure of one of the RAID physical disks configured with a physical disk having a capacity equal to or smaller than the physical disks 230 and 231 of the hot spare 320 May occur, a state after a physical disk having a capacity equal to or larger than that of the hot spare 320 is incorporated may be in a state.

  Then, as an operation of the disk array device 10, a new physical disk that has been replaced due to a failure is not limited to being incorporated into the original RAID configuration, but can also be used as a new hot spare 320. In this case, for example, when a 2 TB physical disk is incorporated from the hot spare 320 instead of a physical disk having a capacity of 1 TB as a RAID configuration, 1 TB becomes an unused area. For example, the physical disk 214 in the RAID 311 of the disk array device 10 in FIG. 2 corresponds to this case.

  In addition, regarding a threshold value set in advance as a capacity threshold value used for monitoring the usage amount of the disk pool 300 by the disk pool monitoring unit 121, for example, when the threshold value is set to 90%, the normal value of the disk array device 10 In the operation mode, for example, when reaching about 80% before the threshold is reached, it is generally performed to examine the expansion of the physical disk and the procedure for expanding the disk pool 300. However, even in such an operation mode, when the above threshold is reached without being able to add a physical disk in time, emergency extension using the unused areas 401 and 402 is used as described above. It will move to the status of the state.

(Description of the effect of this embodiment)
As described in detail above, the following effects can be achieved in the disk array device 10 of the present embodiment.

  That is, in the present embodiment, it is possible to avoid a business stop caused by a lack of capacity of the disk pool 300, and to continue the business. The reason is that the disk pool 300 is temporarily expanded in an emergency by using the capacity of the unused areas 401 and 402 generated in consideration of the capacity difference in the physical disk forming the RAID configuration. This is because it is possible to avoid a shortage of capacity.

  The disk array device 10 according to the present embodiment has a function of providing a virtual volume having a capacity larger than the actual capacity of the disk pool as a virtual volume to external devices such as the servers 21 and 22 by the thin provisioning function. In the device, it is possible to adapt particularly effectively.

(Other embodiments of the present invention)
Next, another embodiment of the present invention different from the embodiment of the disk array device 10 shown in FIG. 1 will be described. In the disk array device 10 of FIG. 1 described above, the connections between the disk array device 10 and the servers 21 and 22 that allocate virtual volumes as logical volumes from the disk array device 10 are, for example, Fiber Channel or iSCSI ( A case has been described in which the virtual volume can be directly recognized by the server 21 and the server 22 through direct physical connection using the Internet Small Computer Systems Interface). However, the present invention is not limited to such a connection type, and may be a system in which the server 21 and the server 22 use a virtual volume as a network drive via a network.

  The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such embodiments are merely examples of the present invention and do not limit the present invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention.

10 disk array device 21 server 22 server 30 management terminal 100 control unit 111 host management unit 112 RAID / hot spare management unit 113 disk pool management unit 114 disk pool expansion unit 115 physical disk management unit 121 disk pool monitoring unit 122 unused area management unit 123 Emergency capacity securing unit 124 Emergency state recovery unit 200 Disk unit 210 to 214 Physical disk 220 to 214 Physical disk 230, 231 Physical disk 300 Disk pool 311 RAID
312 RAID
320 Hot spare 401 Unused area 402 Unused area

Claims (10)

Providing a virtual volume by forming a disk pool that collectively manages the capacity of each physical disk constituting one or more RAIDs;
Disk pool monitoring means for monitoring whether the used capacity of the disk pool has reached a threshold;
Unused area management means for securing and managing an unused area generated in each of the physical disks as a capacity for expanding an emergency disk pool;
And an emergency capacity securing unit that temporarily allocates the unused area as a capacity expansion volume of the disk pool when the used capacity of the disk pool reaches the threshold based on the monitoring result. A disk array device. A thin provisioning function capable of allocating a virtual volume having a capacity larger than the actual capacity of the disk pool to an external device as a logical volume;
The disk array device according to claim 1, further comprising: When the unused area is temporarily allocated as a capacity expansion volume of the disk pool by the emergency capacity securing unit, a management terminal that manages the disk array apparatus, and further, the disk pool of the disk array apparatus The disk array device according to claim 1 or 2, wherein when there is the external device used as a virtual volume, the external device is notified. Based on the result of the monitoring, when the capacity of the disk pool is expanded by a new addition of a physical disk in the emergency expansion state due to the used capacity of the disk pool reaching the threshold value, After the data written to the unused area temporarily allocated as the capacity expansion volume is moved to a new area in the newly added physical disk, the capacity expansion volume is moved. The disk array device according to any one of claims 1 to 3, further comprising emergency state return means for releasing and returning to the original unused area. When the unused area temporarily allocated as the capacity expansion volume of the disk pool is returned to the original state by the emergency return means, the emergency extension state has returned to the normal state. The management terminal that manages the disk array device, and further, when there is the external device that uses the disk pool of the disk array device as a virtual volume, is notified to the external device. The disk array device according to claim 4. Extending the capacity of the disk pool of a disk array device that provides a virtual volume by forming a disk pool that collectively manages the capacity of each physical disk constituting one or more RAIDs;
A disk pool monitoring step for monitoring whether the used capacity of the disk pool has reached a threshold;
An unused area management step for securing and managing an unused area generated in each of the physical disks as a capacity for expanding an emergency disk pool;
An emergency capacity securing step for temporarily allocating the unused area as a capacity expansion volume of the disk pool when the used capacity of the disk pool reaches the threshold based on the monitoring result. A disk pool capacity expansion method characterized by the above. A thin provisioning function capable of allocating a virtual volume having a capacity larger than the actual capacity of the disk pool to an external device as a logical volume;
The disk pool capacity expansion method according to claim 6, further comprising: When the unused area is temporarily allocated as a capacity expansion volume of the disk pool in the emergency capacity securing step, the management terminal that manages the disk array device, and further the disk pool of the disk array device The disk pool capacity expansion method according to claim 6 or 7, wherein when there is the external device used as a virtual volume, the external device is notified. Based on the result of the monitoring, when the capacity of the disk pool is expanded by a new addition of a physical disk in the emergency expansion state due to the used capacity of the disk pool reaching the threshold value, After the data written to the unused area temporarily allocated as the capacity expansion volume is moved to a new area in the newly added physical disk, the capacity expansion volume is moved. The disk pool capacity expansion method according to any one of claims 6 to 8, further comprising an emergency state return step of releasing and returning to the original unused area. When the unused area temporarily allocated as the capacity expansion volume of the disk pool is restored to the original state by the emergency return step, the emergency extension state is restored to the normal state. The management terminal that manages the disk array device, and further, when there is the external device that uses the disk pool of the disk array device as a virtual volume, is notified to the external device. The disk pool capacity expansion method according to claim 9.

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