JP2015170271A - Storage area management apparatus, storage area management method, and storage area management program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage area management apparatus capable of restraining a storage area allocated to a virtual disk from increasing when a swap area of the virtual disk in shin format is accessed.SOLUTION: The storage area management apparatus according to the present invention comprises: request detection means for detecting a write request to a swap area in an allocation area which is a storage area allocated by a virtual machine; management means for associating a target region to which a write is requested by the write request in the swap area in which the write request is detected, with a region in a swap storage area allocated to the swap area from an another storage area not included in the allocation area; and request execution means for executing the write based on the write request to a use region, the region associated with the object region.

Description

  The present invention relates to a technique for managing allocation of storage areas.

  Patent Document 1 describes a virtual server on which a virtual machine operates. A dedicated swap disk on the storage is assigned to the virtual machine. The virtual server of Patent Document 1 includes a swap drive memory that caches I / O (Input / Output) for a swap disk.

  Patent Document 2 describes a computer that creates a swap file when the swap area is insufficient, adds the created swap file to the swap area, and deletes the added swap file when the swap area remains. Yes.

  Patent Document 3 describes an information processing apparatus that allocates a swap area having a required size to a free area of a magnetic disk device if the memory capacity required for starting the application program is smaller than the mounted memory capacity when the application program is started. ing. The information processing apparatus of Patent Document 3 releases the allocated swap area when the application program ends.

JP 2013-196421 A JP-A-6-052059 JP-A-6-168184

  As a method of reducing the storage area used for the virtual disk, there is a method called thin provisioning. In thin provisioning, a storage system that provides a virtual disk allocates a storage area only to a partial area of the virtual disk in an initial state, for example, not the entire storage area set as the virtual disk. Then, the storage system adds a storage area allocated to the virtual disk according to the usage amount of the virtual disk. For example, when writing is performed on the virtual disk, the storage system newly allocates a storage area to the portion where the virtual disk is written. Then, the storage system stores the data written in the allocated storage area. The information processing apparatus accesses a virtual disk constructed based on thin provisioning in the same manner as when accessing a disk not based on thin provisioning. In the following description, a virtual disk constructed by thin provisioning will be referred to as a thin virtual disk or simply as a thin disk.

  In many file systems, to avoid storage fragmentation, data stored in storage is deleted by changing the metadata of the deleted data to a value that indicates that it is unused. Is called. The data newly stored in the storage is written to the area where no data has been written since the file system was created.

  When such a file system is used in a thin disk, the storage area allocated to the thin disk increases as the number of data writes and deletions increases. When the swap area is allocated to the thin disk, the storage area allocated to the thin disk increases as the swap occurs.

  In the technique of Patent Document 1, when writing exceeding the capacity of the swap drive memory occurs in the swap area, writing occurs on the swap disk. In the technique of Patent Document 1, when the swap disk is a thin disk, it is not possible to suppress an increase in the storage area allocated to the thin disk in accordance with writing to the swap disk.

  The computer described in Patent Document 2 creates a swap file as necessary. And when the created swap file becomes unnecessary, the computer described in patent document 2 deletes the swap file. When a swap file is created on a thin disk, the amount of storage area allocated to the thin disk increases as the swap file is created and deleted.

  The information processing apparatus described in Patent Document 3 creates a swap area in a free area of a magnetic disk device. Then, when the created swap area becomes unnecessary, the information processing apparatus described in Patent Document 3 deletes the swap area. When the magnetic disk device is a virtual magnetic disk device constructed based on thin provisioning, the capacity of the storage area allocated to the virtual magnetic disk device depends on the repeated creation and deletion of the swap area. To increase.

  That is, in the techniques of Patent Documents 1 and 2, when the storage device accessed by the information processing device is a thin disk, the storage allocated to the storage device increases in accordance with writing and deletion to the swap area in the storage device. The increase in area cannot be suppressed.

  One of the objects of the present invention is to provide a storage area management device capable of suppressing an increase in storage area allocated to a virtual disk accompanying access to a swap area in a thin virtual disk. .

  The storage area management apparatus according to the present invention includes a request detection unit that detects a write request to a swap area in an allocated area that is a storage area allocated to a virtual machine, and the write in the swap area in which the write request is detected. Management means for associating a target area that is requested to be written by a request with an area in a swap storage area that is allocated to the swap area from another storage area that is not included in the allocated area, and that is associated with the target area Request execution means for performing writing based on the write request to the use area, which is the area.

  The storage area management method of the present invention detects a write request to a swap area in an allocation area that is a storage area allocated to a virtual machine, and writing is performed by the write request in the swap area where the write request is detected. The requested target area is associated with the area in the swap storage area allocated to the swap area from another storage area not included in the allocated area, and the used area that is the area associated with the target area On the other hand, writing based on the write request is performed.

  The storage area management program according to the present invention includes a request detection unit that detects a write request to a swap area in an allocation area that is a storage area allocated to a virtual machine, and a swap area in which the write request is detected. A management means for associating a target area that is requested to be written by the write request with an area in a swap storage area that is allocated to the swap area from another storage area that is not included in the allocated area; and It operates as a request execution means for performing writing based on the write request with respect to the use area which is the associated area.

  The present invention has an effect that it is possible to suppress an increase in a storage area allocated to a virtual disk accompanying access to a swap area in a thin virtual disk.

FIG. 1 is a diagram illustrating a configuration of an information processing system 100 according to the first embodiment. FIG. 2 is a diagram schematically illustrating a thin disk that is a virtual disk constructed by thin provisioning. FIG. 3 is a diagram schematically illustrating the arrangement of the use area and the release area before and after the rearrangement. FIG. 4 is a diagram schematically illustrating an example of the location of the target area and the use area that are associated with each other and stored in the area information storage unit 13. FIG. 5 is a diagram schematically illustrating a second example of the location of the target area and the use area that are associated with each other and stored in the area information storage unit 13. FIG. 6 is a diagram schematically illustrating an example of the location of the release area stored in the area information storage unit 13. FIG. 7 is a diagram schematically illustrating a second example of the location of the release area stored in the area information storage unit 13. FIG. 8 is a flowchart illustrating an example of the operation of the storage area management device 1 according to the first embodiment when the virtual machine 20 starts the operation. FIG. 9 is a flowchart illustrating an example of the operation of the storage area management device 1 according to the first embodiment when the virtual machine 20 is stopped. FIG. 10 is a flowchart illustrating an example of an operation when the virtual machine 20 transmits an access request in the storage area management apparatus 1 according to the first embodiment. FIG. 11 is a flowchart illustrating an example of an operation of the storage area management device 1 according to the first embodiment when the virtual machine 20 transmits a release request command. FIG. 12 is a diagram schematically illustrating functions of an implementation example based on the first embodiment. FIG. 13 is a block diagram schematically illustrating functions that operate when the virtual machine 20 is activated in the hypervisor 22A. FIG. 14 is a block diagram schematically illustrating functions that operate when the virtual machine 20 stops in the hypervisor 22A. FIG. 15 is a block diagram schematically illustrating functions that operate when the guest OS 21 performs I / O. FIG. 16 is a block diagram schematically illustrating a function that operates when the area release function 102 of the guest OS 21 makes an area release request. FIG. 17 is a block diagram schematically illustrating a function that operates when the release area management function 204 reduces the capacity of the swap area file 302. FIG. 18 is a flowchart illustrating an example of the operation of the storage area management device 1 when the virtual machine 20 transmits an area release command. FIG. 19 is a flowchart illustrating an example of an operation of rearranging used areas in the storage area management apparatus 1. FIG. 20 is a block diagram showing the configuration of the storage area control device 1A of this embodiment. FIG. 21 is a diagram illustrating an example of a configuration of a computer 1000 that can implement the storage area management apparatus 1, the storage area management apparatus 1A, the information processing apparatus 2, and the information processing apparatus 2A.

  Next, an embodiment of the present invention will be described.

<First Embodiment>
First, a first embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of an information processing system 100 according to the present embodiment.

  Referring to FIG. 1, the present embodiment includes an information processing device 2 and a storage device 3. The information processing device 2 and the storage device 3 are connected to each other. The information processing device 2 includes a storage area management device 1.

  The storage area management device 1 includes a request detection unit 10, a management unit 11, a request execution unit 12, a region information storage unit 13, a relocation unit 14, a release unit 15, an operation detection unit 16, and a swap area. A detection unit 17, a deletion unit 18, and a securing unit 19 are included.

  The information processing apparatus 2 further includes a virtual machine execution unit 22 that executes the virtual machine 20. In the virtual machine 20, a guest OS (Operating System) 201 is operating. The virtual machine execution unit 22 is generally realized by software called a hypervisor that realizes the virtual machine 20 and a processor of the information processing apparatus 2 that executes the hypervisor. The virtual machine 20 is an emulated computer. An application program may be running on the guest OS 21 running on the virtual machine 20. Hereinafter, a case where the number of virtual machines 20 is one will be described. However, a plurality of virtual machines 20 may be operating.

  Note that the hypervisor may have a function of realizing each component of the storage area management device 1. A processor that executes the hypervisor may operate as the storage area management apparatus 1.

  In the following description, the fact that the processor that executes the guest OS 21 transmits an access request is referred to as “the virtual machine 20 transmits an access request”. Similarly, an application program operating in the guest OS 21 sending an access request via the guest OS 21 is also expressed as “the virtual machine 20 sends an access request”.

  The access request is, for example, an access request for an allocation area 301 described later. The access request is, for example, a read request that is a request for reading data stored in the allocation area 301. The access request is, for example, a write request that is a request for writing data in the allocation area 301. The access request is, for example, a release request that is a request to return at least a part of the area used in the swap area to a state where it is not used. The request includes the type of request and a data value representing the area that is the target of the request. The access request may be another request. The request type is, for example, write, read, release, etc. The area that is the target of the request is, for example, a range that is accessed by the access request in the storage area allocated to the information processing apparatus 2 that transmits the access request. In the following description, an area that is a request target will be referred to as a target area. When the access request is a read request, the access area is a range in which read data is stored. When the access request is a write request, the access area is an area where writing is performed. When the access request is a release request, the target area is an area that is returned to the unused state. In the following description, the access request is also expressed as a request command.

  The storage device 3 includes an allocation area 301 that is a storage area constructed as the above-described thin disk, and a swap storage area 302. In the following description, the allocation area 301 is also referred to as a thin disk 301. The storage device 3 is realized by, for example, one or more storage devices. The storage device is, for example, a hard disk device or an SSD (Solid State Drive). The swap storage area 302 is a storage area different from the allocation area 301. The swap storage area 302 may be a file created in a storage area different from the allocation area 301. In the following description, the swap storage area 302 is also referred to as a swap area file 302.

  FIG. 2 is a diagram schematically showing a thin disk, that is, a virtual disk constructed by thin provisioning. The storage area is a storage area realized by a hard disk device or another storage device. The virtual disk 1 and the virtual disk 2 are virtual storage devices constructed by thin provisioning by a storage controller (not shown), for example. The information processing apparatus 2 using the virtual disk can access the virtual disk in the same way as accessing a physical storage device. However, the storage area is allocated from the storage area only to the used area among the storage areas accessible from the information processing apparatus 2 as the storage area of the virtual disk. The used area is, for example, an area where data has been written even once. A storage area is not allocated to an area that is not used. In the example illustrated in FIG. 2, storage areas are allocated from the storage area to the written areas of the virtual disk 1 and the virtual disk 2. The written area is the area used as described above.

  The allocation area 301 is a storage area allocated to the virtual machine 20. A target area that is an access target according to an access request transmitted by the virtual machine 20 is any area included in the allocation area 301.

  The swap storage area 302 is a storage area that exists in a storage area different from the allocation area 301. The swap storage area 302 may be secured in a storage area in a thin format disk. The swap storage area 302 may not be secured in the storage area of the thin format disk.

  In the following, a case where there is one virtual machine 20, one swap area included in the allocation area 301, and one swap storage area 302 will be mainly described. The virtual machine 20, the swap area included in the allocation area 301, and the swap storage area 302 may be plural.

  Next, components of the storage area management apparatus 1 will be described.

  The operation detection unit 16 detects the start of the virtual machine 20 and the stop of the operation of the virtual machine 20. Activation is when the virtual machine 20 starts operation. Activation includes returning from the suspended state. Stopping the operation includes transition to the suspended state. When the activation of the virtual machine 20 is detected, the operation detection unit 16 may further detect whether the activation of the virtual machine 20 is a return from the suspended state.

  When activation of the virtual machine 20 is detected, the operation detection unit 16 determines whether or not there is a swap storage area 302 associated with the swap area of the virtual machine 20 for which activation has been detected. When the activation of the virtual machine 20 is detected, and when the detected activation is a return from the suspended state, the operation detection unit 16 performs swap storage associated with the swap area of the virtual machine 20 where the activation is detected. It may be determined whether or not the region 302 exists.

  When the swap storage area 302 is a file created in a storage area included in the storage device 3, the swap storage area 302 is also expressed as a swap area file 302 as described above. In this case, the operation detection unit 16 may determine whether or not there is a swap area file 302 associated with the virtual machine 20 whose activation has been detected. Furthermore, when there is one virtual machine 20, the operation detection unit 16 may determine whether or not the swap area file 302 exists.

  When there is a swap storage area 302 associated with the swap area of the virtual machine 20 whose activation has been detected, the storage area management device 1 determines that the swap storage is present in the swap area of the virtual machine 20. The state in which the area 302 is associated is continued.

  When there is no swap storage area 302 associated with the swap area of the virtual machine 20 whose activation has been detected, the swap area detection unit 17 opens the allocation area 301 allocated to the virtual machine 20 whose activation has been detected. . Then, the swap area detection unit 17 detects the swap area in the allocation area 301 and specifies the location of the detected swap area. The swap area detection unit 17 may store the location of the detected swap area in, for example, the area information storage unit 13. The swap area detecting unit 17 may transmit the location of the detected swap area to the securing unit 19. The location of the swap area or other area is represented by, for example, the start address of the area and the size of the area. Alternatively, the location of the swap area or other area may be represented by, for example, the start address of the area and the end address of the area. For example, the address indicating the location of the swap area may be represented by a logical address used for accessing the allocation area 301 by the virtual machine 20.

  The securing unit 19 creates the swap storage area 302 when the activation of the virtual machine 20 is detected. The securing unit 19 further initializes a later-described release area list stored in the area information storage unit 13. As will be described later, the release area is a storage area in which data is written as the swap storage area 302 at least once, and then the area release described later is performed. The release area list is a set of positions of the respective release areas. The securing unit 19 further expands the size of the secured swap storage area 302 based on, for example, a securing instruction from the management unit 11. The securing instruction only needs to include the size. The securing unit 19 may secure, for example, a storage area having a size based on an instruction starting from the next address at the end of the existing swap storage area 302 and merging the secured storage area with the swap storage area 302.

  For example, when the activation of the virtual machine 20 is detected, the securing unit 19 determines the initial position of the swap storage area 302 in a storage area included in the storage apparatus 3 and different from the allocation area 301.

  The securing unit 19 may determine the start address of the swap storage area 302 as the initial position of the swap storage area 302. For example, the reservation unit 19 may set the start address of the storage area in which the swap storage area 302 is reserved as the start address of the swap storage area 302.

  The securing unit 19 may determine only the start address of the swap storage area 302 as the initial position of the swap storage area 302. In this case, if the swap storage area 302 is the swap area file 302, the securing unit 19 may create a swap area file 302 file having a size of 0, for example.

  The securing unit 19 may further secure a swap storage area 302 having a predetermined size starting from the position represented by the determined leading address. Then, the securing unit 19 may store, in the area information storage unit 13, a location represented by, for example, the start address and the size of the swap storage area 302.

  If there is a release area list including at least one release area location, the securing unit 19 may initialize the release area list by deleting the release area list. When the release area list does not exist, the securing unit 19 does not have to do anything to initialize the release area list.

  When the operation detecting unit 16 detects that the operation of the virtual machine 20 is stopped, the deleting unit 18 determines whether or not the reserved swap storage area 302 can be released. When the swap storage area 302 is realized by a file, the deletion unit 18 may determine whether or not the swap area file 302 that is the swap storage area 302 can be deleted.

  The deleting unit 18 may determine whether or not the swap storage area 302 can be released by determining whether or not a dump file is stored in the swap storage area 302, for example. When the dump file is stored in the swap storage area 302, the deletion unit 18 may determine that the swap storage area 302 cannot be released. If no dump file is stored in the swap storage area 302, the deletion unit 18 may determine that the swap storage area 302 can be released. The deletion unit 18 may first determine whether the stop of the operation of the virtual machine 20 is a transition to the suspended state. In this case, when the stop of the operation of the virtual machine 20 is the transition to the suspended state, the deletion unit 18 may determine that the swap storage area 302 cannot be released. When the stop of the operation of the virtual machine 20 is not the transition to the suspended state, the deletion unit 18 further determines whether or not the dump file is stored in the swap storage area 302, thereby releasing the swap storage area 302. What is necessary is just to determine whether it is possible.

  If it is determined that the reserved swap storage area 302 can be released, the deletion unit 18 releases the swap storage area 302. That is, the deletion unit 18 releases the allocation of the swap storage area 302 to the swap area of the virtual machine 20. Further, the swap storage area 302 secured in the storage area included in the storage apparatus 3 and not the allocation area 301 is released. When the swap storage area 302 is realized by a file, the deletion unit 18 may delete the swap area file 302 that is the swap storage area 302.

  The request detection unit 10 detects an access request transmitted by the virtual machine 20. Then, the request detection unit 10 specifies the request type and the target area based on the detected access request. Further, the request detection unit 10 compares the location of the target area with the location of the swap area, for example, whether or not the target area specified based on the received access request is included in the swap area of the allocation area 301. Judgment by. For example, the location of the swap area in the allocation area 301 may be stored in the area information storage unit 13.

  If the identified target area is not included in the swap area of the allocation area 301, the management unit 11 transmits the access request detected by the request detection unit 10 to the request execution unit 12 as it is.

  Upon receiving the access request, the request execution unit 12 performs access according to the access request. When the identified target area is not included in the swap area of the allocation area 301, the access destination of the access performed by the request execution unit 12 is the allocation area 301.

  When the specified target area is included in the swap area of the allocation area 301, the request detection unit 10 further specifies the type of access request.

  When the type of the identified access request is read, the management unit 11 identifies an area included in the swap storage area 302 that is associated with the target area accessed by the detected access request. As will be described later, the information indicating the association between the target area and the area included in the swap storage area 302 may be stored in the area information storage unit 13. The management unit 11 uses the swap storage area 302 associated with the target area based on information indicating the association between the target area stored in the area information storage unit 13 and the area included in the swap storage area 302. What is necessary is just to specify the area | region contained in.

  When the identified access request type is write, the management unit 11 determines whether the target area accessed by the detected access request is associated with any area included in the swap storage area 302. When the target area accessed by the detected access request is associated with the area included in the swap storage area 302, the management unit 11 requests, for example, the start address of the area associated with the target area. It transmits to the execution part 12. In this case, the management unit 11 may transmit the detected access request and the start address of the area associated with the target area to the request execution unit 12 as the start address of the area accessed by the access request. .

  When the target area accessed by the detected access request is not associated with any area included in the swap storage area 302, the management unit 11 associates the area included in the swap storage area 302 with the target area. . The area newly associated with the target area by the management unit 11 is, for example, an area that is not smaller than the size of the target area and is not associated with any other target area.

  The management unit 11 first determines whether there is a continuous release area whose size is equal to or larger than the size of the target area based on the release area list stored in the area information storage unit 13. When there is a continuous release area whose size is equal to or larger than the size of the target area, the management unit 11 selects, for example, an area having a size equal to or larger than the size of the target area starting from the head of the release area. What is necessary is just to link | relate with an object area | region as a use area | region. Then, the management unit 11 may transmit the start address of the storage area associated with the target area as the use area to the request execution unit 12.

  When there is no continuous release area whose size is equal to or larger than the size of the target area, the management unit 11 determines whether the total size of the release areas is equal to or larger than the size of the target area. When the total size of the released areas is equal to or larger than the size of the target area, the size of the target area and a request for rearrangement of the used area are transmitted to the rearrangement unit 14. In the description of this embodiment, “relocation of used areas” refers to moving used areas in the swap storage area 302 so that the used areas are continuous. In the following description, “relocation of used areas” is also referred to as “defragmentation”.

  The rearrangement unit 14 that has received the size of the target area and the request for rearrangement of the used area, for example, until a continuous release area having a size equal to or larger than the size of the target area is generated. The use area is moved within 302. The rearrangement unit 14 may move the use area so that the use area is continuous in the swap storage area 302. In other words, the rearrangement unit 14 rearranges the used areas to generate a continuous release area having a size equal to or larger than the target area in the swap storage area 302.

  Note that the management unit 11 may transmit only a request to rearrange the used area to the rearrangement unit 14 without transmitting the size of the target area. In this case, the rearrangement unit 14 may move the use area so that all the use areas are continuous in the swap storage area 302, for example. For example, the management unit 11 uses, as a used area, an area having a size greater than or equal to the size of the target area starting from the beginning of the release area whose size is equal to or larger than the size of the target area after the used area has moved. As long as it is associated with the target area. Then, the management unit 11 may transmit the start address of the storage area associated with the target area as the use area to the request execution unit 12.

  FIG. 3 is a diagram schematically illustrating the arrangement of the use area and the release area before and after the rearrangement. For example, when a use area exists at a position represented by “placement before rearrangement” on the left side of FIG. 3, the use areas are not continuous. Further, the release area is divided into two. When the rearrangement unit 14 rearranges the swap storage area 302 in which the use area and the release area are arranged as shown on the left side of FIG. 3, the rearrangement unit 14 is arranged on the right side of FIG. The use area is moved so that The rearrangement unit 14 first stores the data stored in the used area before the movement at the position of the used area after the movement. Then, the rearrangement unit 14 updates the location of the used area and the location of the release area stored in the area visit storage unit 11 according to the location of the used area after movement. The location of the use area and the release area may be represented by, for example, the start address and size of these areas. The location of the use area and the release area may be represented by, for example, the start address and the end address of these areas. The address indicating the location of the used area and the released area may be a common address used when each component of the storage area management device 1 accesses the swap area 302, for example.

  The relocation unit 14 may further reduce the size of the swap storage area 302 by excluding the release area from the swap storage area 302.

  When a continuous release area whose size is equal to or larger than the size of the target area is generated by the rearrangement performed by the rearrangement unit 14, the management unit 11, for example, selects the target area from among the continuous release areas. An area that is equal to or larger than is associated with the target area as a use area.

  For example, the management unit 11 stores the location of the target area associated with the use area and the location of the use area associated with the target area in the area information storage unit 13. As described above, the location of the storage area such as the target area or the use area is represented by, for example, the start address of the storage area and the size of the area.

  The area information storage unit 13 stores the locations of the target area and the used area that are associated with each other. The area information storage unit 13 stores the location of the release area. Further, the area information storage unit 13 stores the location of the swap storage area 302. The area information storage unit 13 may further store the location of the swap area in the allocation area 301. As described above, the data indicating the location of the release area stored in the area information storage unit 13 is the release area list. The release area list may be stored in the area information storage unit 13 in the form of a table.

  FIG. 4 is a diagram schematically illustrating an example of the location of the target area and the use area that are associated with each other and stored in the area information storage unit 13. In the example shown in FIG. 4, the start address and size of the target area are associated with the start address and size of the used area. As described above, the start address and size of the storage area indicate the location of the storage area. The target area address is an address used by the virtual machine 20 to specify an access destination in the allocation area 301. The used area address is an address used by the storage area management device 1 to specify an access destination in the swap storage area 302.

  FIG. 5 is a diagram schematically illustrating a second example of the location of the target area and the use area that are associated with each other and stored in the area information storage unit 13. When there are a plurality of virtual machines 20, it is only necessary that a virtual machine ID that is an identifier of the virtual machine 20 is included in the location of the target area, as in the example illustrated in FIG. When the number of virtual machines 20 is one, the virtual machine ID may not be included in the location of the target area. Further, when there are a plurality of swap storage areas 302, the area ID that is the identifier of the swap storage area 302 may be included in the location of the used area. When only one swap storage area 302 is secured, the area ID may not be included in the location of the used area.

  FIG. 6 is a diagram schematically illustrating an example of the location of the release area stored in the area information storage unit 13. In the description of this embodiment, the release area list indicating the location of each release area is also referred to as a release area data value. The address of the release area is an address used by the storage area management device 1 to specify an access destination in the swap storage area 302.

  FIG. 7 is a diagram schematically illustrating a second example of the location of the release area stored in the area information storage unit 13. When there are a plurality of swap storage areas 302 as in the example illustrated in FIG. 7, the area ID that is the identifier of the swap storage area 302 may be included in the location of the release area. When only one swap storage area 302 is secured, the area ID may not be included in the location of the release area.

As described above, when there is a used area associated with the target area, the management unit 11 uses, for example, the used area associated with the target area that is an access target based on the access request received by the request detection unit 10. The head address may be transmitted to the request execution unit 12. Similarly, when the used area secured in the release area is associated with the target area, the management unit 11 similarly uses, for example, the used area associated with the target area to be accessed based on the access request received by the request detection unit 10. The head address may be transmitted to the request execution unit 12.

  When the total size of the release areas is smaller than the size of the target area, the management unit 11 is determined based on the size of the target area, for example, starting from the address next to the last address of the existing use area. The size area may be associated with the target area as the use area. Then, the management unit 11 may transmit to the request execution unit 12 the next address after the existing used area final address as the start address of the used area related to the target area. In this case, the swap storage area 302 only needs to be secured in a sufficiently large storage area. It is sufficient that a sufficiently large storage area continuous to the swap storage area 302 can be secured as the swap storage area 302.

  In this case, the management unit 11 may expand the swap storage area 302 before transmitting the use area start address associated with the target area to be accessed by the received write request to the request execution unit 12. The extension size, which is the size of the expanded portion of the swap storage area 302, is the end address of the swap storage area 302 and the end of the use area associated with the target area added to the end of the existing use area. Any difference from the address may be used.

  When the total size of the release areas is smaller than the size of the target area, the management unit 11 may first instruct the rearrangement unit 14 to perform rearrangement. Then, the management unit 11 uses, as a use area, an area having a size determined based on the size of the target area, starting from the address next to the final address of the existing use area after the rearrangement. It may be associated with a region.

  When the access type specified in the access request detected by the request detection unit 10 is release, the release unit 15 releases the target area in the access request. That is, the release unit 15 cancels the association between the target area in the access request and the used area associated with the target area. The release of the target area is, for example, that the virtual machine 20 does not use the target area that has been used as a part of the swap area as the swap area.

  When the swap storage area 302 is the swap area file 302, the release unit 15 may perform processing for excluding the target area to be released from the swap area file 302 and reducing the size of the swap area file 302, for example. Good. In that case, the release unit 15 may update the release area list. That is, the release unit 15 stores the data value indicating the location of the area excluded from the swap area file 302 by the release in the area information storage unit 13.

  The release unit 15 may delete the location of the target area and the location of the used area associated with the location of the target area, which are stored in the area information storage unit 13, for example. As a result, the release unit 15 may cancel the association between the target area of the access request whose type is release and the used area associated with the target area. That is, the release unit 15 deletes the location of the target area of the access request whose type is release and the location of the used area associated with the target area from the area information storage unit 13, thereby deleting the target area. Release it.

  Further, the release unit 15 updates the release area list, that is, the release area data value stored in the area information storage unit 13 so that the use area associated with the released target area is included in the release area. When the released area list, that is, the released area data value is represented by the used area location shown in FIG. 4, for example, the used area location associated with the released target area is deleted as described above. As a result, the used area whose location has been deleted is added to the released area. When the area information storage unit 13 stores a release area list such as the example illustrated in FIG. 5, for example, the release unit 15 uses, for example, a use area associated with the target area of the access request whose type is release. May be added to the release area list.

  The release unit 15 may hold the access request detected by the request detection unit 10 and whose access type is release until a predetermined condition is satisfied. The release unit 15 holds the location of the release target area, which is the target storage area to be released by the access request whose access type is release, not the access request whose access type is release until a predetermined condition is satisfied. You may do it. Then, when a predetermined condition is satisfied, the release unit 15 may release the held release target areas, for example, collectively. The release unit 15 determines whether or not a predetermined condition is satisfied, and releases the target area based on the determination result, for example, periodically in the background (that is, processing performed in response to an access request) In parallel).

  The predetermined condition described above is, for example, that the total size of the release target areas held by the release unit 15 exceeds a predetermined value. The predetermined condition is, for example, that an index representing the load on the storage device 3 is below a predetermined value. The index representing the load on the storage device 3 is, for example, the amount of I / O to the storage device 3. The I / O amount may be, for example, the number of access requests per unit time. The I / O amount may be, for example, the amount of data transferred per unit time. The I / O amount may be another amount. The index indicating the load on the storage device 3 may be another index. The predetermined condition may be, for example, that the free capacity of the swap storage area 302 is less than a predetermined capacity. The predetermined condition may be a combination of the conditions described above.

  After releasing the target area, the release unit 15 may make a request to the rearrangement unit 14 to perform rearrangement of the used area, that is, defragmentation.

  For example, the relocation unit 14 that has received the use area relocation request moves the use area so that the locations of the use areas included in the swap storage area 302 are continuous. The rearrangement unit 14 may perform rearrangement of the use area in the background in the same manner.

  Next, the operation of the storage area management apparatus 1 of the present embodiment will be described in detail with reference to the drawings.

  First, the operation of the storage area management device 1 according to the present embodiment when the virtual machine 20 starts operation will be described.

  FIG. 8 is a flowchart illustrating an example of the operation of the storage area management device 1 according to the present embodiment when the virtual machine 20 starts the operation.

  When the virtual machine 20 is activated, the operation detection unit 16 detects activation of the virtual machine 20 (step S101). For example, the virtual machine execution unit 22, which is a hypervisor that emulates the virtual machine 20, may transmit a notification of activation of the virtual machine 20 to the operation detection unit 16. The operation detection unit 16 may determine that the virtual machine 20 has started when receiving a notification of the start of the virtual machine 20.

  The operation detection unit 16 further determines whether or not the activation of the virtual machine 20 is a return from suspend. For example, the virtual machine execution unit 22, which is a hypervisor that emulates the virtual machine 20, may transmit a signal indicating whether the activation of the virtual machine 20 is a return from suspend to the operation detection unit 16. The operation detection unit 16 determines whether the activation of the virtual machine 20 is a return from suspend based on the signal received from the virtual machine execution unit 22 and indicating whether the activation of the virtual machine 20 is a return from suspend. What is necessary is just to determine. The operation detection unit 16 may determine whether the activation of the virtual machine 20 is a return from suspend by another method.

  When the activation of the virtual machine 20 is a return from suspend (Yes in step S102), the operation illustrated in FIG. 8 ends. In the present embodiment, when the virtual machine 20 shifts to the suspended state, the swap storage area 302 associated with the swap area of the virtual machine 20 is not released. Therefore, when the activation of the virtual machine 20 is the return from the suspend, the swap storage area 302 associated with the swap area of the virtual machine 20 exists. In that case, the storage area management device 1 maintains a state in which the swap area of the virtual machine 20 and the swap storage area 302 are associated with each other.

  If the activation of the virtual machine 20 is not a return from suspend (No in step S102), for example, the operation detection unit 16 determines whether or not the swap storage area 302 exists. When the information processing apparatus 2 is configured so that a plurality of virtual machines 20 operate, the operation detection unit 16 determines that the area of the swap storage area 302 associated with the swap area of the virtual machine 20 from which activation is detected. What is necessary is just to determine whether it exists. The operation detection unit 16 determines the determination by, for example, determining whether the location of the used area associated with the target area included in the swap area of the virtual machine 20 is stored in the area information storage unit 13. Just do it. When the swap storage area 302 is the swap area file 302, the operation detection unit 16 may determine whether or not the swap area file 302 exists in the storage device 3.

  If the swap storage area 302 exists (Yes in step S103), the operation shown in FIG. 8 ends. In that case, the storage area management device 1 maintains a state in which the swap area of the virtual machine 20 and the swap storage area 302 are associated with each other.

  The operation detection unit 16 may determine whether the activation of the virtual machine 20 is a return from suspend by determining whether or not the swap storage area 302 is associated with the swap area of the virtual machine 20. Good. In that case, if there is a swap storage area 302 associated with the swap area of the virtual machine 20, the operation detection unit 16 may determine that the activation of the virtual machine 20 is a return from suspend. Further, the operation detection unit 16 may determine that the activation of the virtual machine 20 is not the return from the suspend if the swap storage area 302 associated with the swap area of the virtual machine 20 does not exist. In this case, the operation detection unit 16 may perform the operations in step S102 and step S103 as the same operation.

  When the swap storage area 302 does not exist (No in step S103), the swap area detection unit 17 opens the allocation area 301 (that is, the thin disk 301) (step S104).

  The swap area detection unit 17 detects a swap area in the allocation area 301 (step S105). For example, the swap area detection unit 17 may detect the swap area by analyzing the structure of the allocation area 301. The swap area detection unit 17 specifies the location of the detected swap area. As described above, the location of the swap area is, for example, a combination of the start address and the size. The location of the swap area may be a combination of the start address and the end address.

  The securing unit 19 secures the swap storage area 302 whose size is equal to or larger than the detected swap area in a storage area different from the allocation area 301 (step S106). When the swap storage area 302 is the swap area file 302, the securing unit 19 creates a swap area file 302 whose size is equal to or larger than the detected swap area size in a storage area different from the allocation area 301. Good.

  The securing unit 19 associates the detected swap area with the swap storage area 302 (step S107). For example, the securing unit 19 may store the detected start address of the swap area and the start address of the swap storage area 302 in the area information storage unit 13 in association with each other.

  The securing unit 19 further initializes the release area list (step S108). For example, the securing unit 19 may set an area for storing a data value that associates the location of the target area with the location of the used area in the area information storage unit 13. When the area information storage unit 13 stores the location of the target area included in the swap area of the virtual machine 20 where the activation is detected and the location of the used area associated with the location of the target area, the securing unit 19 , Delete those places. If it is not necessary to initialize the release area list, the securing unit 19 does not have to do anything in step S108.

  Next, the operation of the storage area management device 1 when the virtual machine 20 is stopped will be described in detail with reference to the drawings.

  FIG. 9 is a flowchart illustrating an example of the operation of the storage area management device 1 according to the present embodiment when the virtual machine 20 is stopped.

  When the virtual machine 20 stops, the operation detection unit 16 detects the stop of the virtual machine 20 (step S201). For example, when the virtual machine 20 stops operating, the virtual machine execution unit 22 that is a hypervisor that emulates the virtual machine 20 may transmit a signal indicating that the virtual machine 20 has stopped to the operation detection unit 16. . The operation detection unit 16 may detect the stop of the virtual machine 20 by receiving a signal indicating that the virtual machine 20 has stopped from the virtual machine execution unit 22.

  For example, the virtual machine 20 stops its operation when the virtual machine 20 is shut down or when the virtual machine 20 is suspended. That is, the stop of the virtual machine 20 includes, for example, shutdown of the virtual machine 20 and suspension of the virtual machine 20 (that is, transition of the virtual machine 20 to the suspended state).

  The operation detection unit 16 determines whether or not the stop of the virtual machine 20 is a suspension of the virtual machine 20. When the stop of the virtual machine 20 is the suspension of the virtual machine 20, that is, when the virtual machine 20 is suspended (Yes in step S202), the storage area management device 1 ends the operation illustrated in FIG. In that case, the association between the swap area of the suspended virtual machine 20 and the swap storage area 302 is maintained. Further, the association between the target area included in the swap area of the virtual machine 20 and the used area included in the swap storage area 302 is also maintained.

  Next, the deletion unit 18 determines whether or not a dump file is stored in the swap storage area 302 (that is, the swap area file 302) (step S203). When the dump file is stored in the swap storage area 302 (Yes in step S203), the storage area management device 1 ends the operation shown in FIG. Also in this case, the association between the swap area of the suspended virtual machine 20 and the swap storage area 302 is maintained. Further, the association between the target area included in the swap area of the virtual machine 20 and the used area included in the swap storage area 302 is also maintained.

  When the dump file is not stored (No in step S203), the deletion unit 18 cancels the association between the swap area of the virtual machine 20 in which the stop is detected and the swap storage area 302 (step S204). For example, the deletion unit 18 may delete the start address of the swap area of the virtual machine 20 and the start address of the swap storage area 302 associated with the swap area from the area information storage unit 13.

  Next, the deletion unit 18 releases the swap storage area 302 secured in the storage apparatus 3 that is associated with the swap area of the virtual machine 20 in which the stop is detected (step S205). When the swap storage area 302 is the swap area file 302, the deletion unit 18 may delete the swap area file 302 associated with the swap area of the virtual machine 20 in which the stop is detected.

  Next, the deletion unit 18 deletes the release area list (step S206). For example, the deletion unit 18 obtains the location of the target area included in the swap area of the virtual machine 20 where the stop has been detected and the location of the used area associated with the location of the target area from the area information storage unit 13. Delete it. The deletion unit 18 may further delete the location of the release area included in the swap storage area 302 associated with the swap area of the virtual machine 20 where the stop is detected from the area information storage unit 13.

  Next, the operation when the virtual machine 20 transmits an access request in the storage area management apparatus 1 of the present embodiment will be described in detail with reference to the drawings.

  FIG. 10 is a flowchart illustrating an example of an operation when the virtual machine 20 transmits an access request in the storage area management apparatus 1 according to the present embodiment. The access request in the example illustrated in FIG. 10 is a write request that is a request to write data in any area included in the allocation area 301 or a read request that reads data from any area included in the allocation area 301. The virtual machine 20 requests access by sending a command. In the following description, the access request is also expressed as a request command. In the example shown in FIG. 10, the type of access request (that is, request command) is write or read.

  When the virtual machine 20 transmits an access request (that is, a request command), the request detection unit 10 detects the request command.

  The request detection unit 10 identifies the type of the detected request command (step S301). As described above, in the example shown in FIG. 10, the type of request command is write or read. Moreover, the request | requirement detection part 10 may perform the operation | movement of step S301 before the operation | movement of step S305, when it is Yes in step S303 mentioned later.

  The request detection unit 10 further specifies a target area that is an area in the allocation area 301 to which access is requested by the detected request command (step S302).

  The request detection unit 10 determines whether or not the specified target area is included in the swap area of the virtual machine 20 that has transmitted the request command (step S303).

  When the identified target area is not included in the swap area of the virtual machine 20 that has transmitted the request command (No in step S303), the request execution unit 12 issues a request command to the allocation area 301 (step S304). . The request execution unit 12 may transmit a request command for requesting access to the target area included in the allocation area 301 to the storage apparatus 3 as it is. In this case, the management unit 11 does not have to do anything with respect to the request command detected by the request detection unit 10. The request execution unit 12 may transmit the execution result of the request command returned from the storage apparatus 3 to the virtual machine 20 via the request detection unit 10, for example.

  When the identified target area is included in the swap area of the virtual machine 20 that has transmitted the request command (Yes in step S303), and when the request command is not a write request (No in step S305), the operation of the storage area management device 1 is as follows. The process proceeds to step S306. If the request command type is not write, the request command type is read.

  In step S306, the management unit 11 specifies a used area associated with the target area. The management unit 11 may read the location of the used area associated with the target area from the area information storage unit 13.

  The request execution unit 12 reads data based on the request command from the specified use area included in the swap storage area 302 (step S307). The request execution unit 12 transmits the read data to the virtual machine 20 via, for example, the request detection unit 10.

  When the request command is a write request (Yes in step S305), the management unit 11 compares the size of the target area with the total size of the release area in the swap storage area 302 (step S308).

  If the size of the target area is smaller than the total size of the release areas in the swap storage area 302 (No in step S308), for example, in step S311, the securing unit 19 adds an area larger than the size of the target area to the swap storage area 302. to add. Then, the securing unit 19 secures a used area having a size equal to or larger than the size of the detected target area in the added area (step S311). The management unit 11 stores the location of the target area and the reserved usage area in the area information storage unit 13 in association with each other. Note that storing the location of the used area associated with the location of the target area in the area information storage unit 13 may ensure the used area.

  If the size of the target area is equal to or larger than the total size of the release areas in the swap storage area 302 (No in step S308), it is determined whether there is a continuous release area larger than the size of the target area. (Step S309).

  If there is a continuous release area larger than the size of the target area in the swap storage area 302 (Yes in step S309), the management unit 11 secures a use area in the continuous release area (step S311). ). The use area secured by the management unit 11 has a size equal to or larger than the size of the detected target area. The management unit 11 stores the location of the target area and the reserved usage area in the area information storage unit 13 in association with each other.

  When there is no continuous release area larger than the size of the target area in the swap storage area 302 (No in step S309), the rearrangement unit 14 rearranges the used areas (step S310). Accordingly, the rearrangement unit 14 generates a continuous release area having a size equal to or larger than the size of the detected target area. The management unit 11 secures a use area having a size equal to or larger than the size of the detected target area in the generated release area. The management unit 11 stores the location of the target area and the reserved usage area in the area information storage unit 13 in association with each other.

  Next, the request execution unit 12 performs writing based on the request command in the reserved use area (step S312).

  Next, the operation of the storage area management device 1 according to the present embodiment when the virtual machine 20 transmits a release request will be described in detail with reference to the drawings.

  FIG. 11 is a flowchart illustrating an example of the operation of the storage area management device 1 according to the present embodiment when the virtual machine 20 transmits a release request command. The release request command is, for example, a command that returns at least a part of the used area included in the swap area to an unused state. When the storage area management device 1 receives the release request command, the storage area management device 1 returns the used area associated with the target area that is the target of the release request command to a state not associated with the target area as follows.

  When the virtual machine 20 transmits a release request command, the request detection unit 10 receives the release request command (step S401). For example, when the request receiving unit 10 that has received the request command from the virtual machine 20 specifies the type of the request command, and the request command type is a release request, the storage area management device 1 is shown in FIG. The operation may be started. In addition, the storage area management device 1 may perform the operation shown in FIG. 11 in the background in parallel with the processing for other request commands.

  Next, the release unit 15 determines whether a predetermined condition is satisfied (step S402).

  As described above, the predetermined condition is, for example, that the total size of the release target areas held by the release unit 15 exceeds a predetermined value. The predetermined condition is, for example, that an index representing the load on the storage device 3 is below a predetermined value. The index representing the load on the storage device 3 is, for example, the amount of I / O to the storage device 3. The I / O amount may be, for example, the number of access requests per unit time. The I / O amount may be, for example, the amount of data transferred per unit time. The I / O amount may be another amount. The index indicating the load on the storage device 3 may be another index. The predetermined condition may be, for example, that the free capacity of the swap storage area 302 is less than a predetermined capacity. The predetermined condition may be a combination of the conditions described above.

  When the predetermined condition is not satisfied (No in Step 403), the release unit 15 stores (that is, holds) the location of the release target area, which is the target area requested to be released by the release request command (Step S403). S404). In the following description, storing the location of the release target area is also referred to as “store the release target area” or “hold the location of the release target area”. The release unit 15 may hold release request command data including a release target area. The operation of the storage area management device 1 returns to step S401 after the operation of step S404.

  When the predetermined condition is satisfied (Yes in Step 403), the release unit 15 releases all the release target areas to be stored (Step S405).

  When the release target area is released, the rearrangement unit 14 rearranges the used area (step S406). As described above, the rearrangement unit 14 may exclude the release area existing at the end of the swap storage area 302 from the swap storage area 302 after the rearrangement of the used areas.

  FIG. 17 is a flowchart showing an example of the operation of receiving the release request command of the storage area management device 1 when the release request command is received and rearranged in parallel. Further, FIG. 18 is a flowchart showing an example of an operation for performing the rearrangement of the storage area management device 1 when the release request command is received and rearranged in parallel. The operation in each step of FIG. 17 and FIG. 18 is the same as the operation in the step given the same reference numeral shown in FIG. The storage area management apparatus 1 may perform the operation shown in FIG. 17 and the operation shown in FIG. 18 in parallel.

  The present embodiment described above has a first effect that it is possible to suppress an increase in the storage area allocated to the virtual disk accompanying access to the swap area in the thin virtual disk.

  The reason is that when the write destination by the access request transmitted by the virtual machine 20 is a swap area included in the allocation area 301 that is a thin virtual disk, the request execution unit 12 writes to the swap storage area 302. Because. The swap storage area 302 is an area secured in a storage area that is not the allocation area 301. As described above, when data writing and deletion are repeated with respect to a general doctor or thin format disk, the size of the storage area allocated to the disk increases. The request execution unit 12 of the present embodiment writes the data requested to be written to the swap area included in the thin allocation area 301 to the swap storage area 302 not included in the allocation area 301. Therefore, an increase in the storage area allocated to the allocation area 301 due to repeated writing to the swap area included in the thin allocation area 301 can be suppressed.

  The present embodiment further has a second effect that the amount of use of the storage area in the storage apparatus 3 can be suppressed.

  The reason is that, when the virtual machine 20 stops operating, the deletion unit 18 increases the free capacity of the storage apparatus 3 by releasing the swap storage area 302 (that is, deleting the swap area file 302). It is.

  This embodiment further has a third effect that an increase in the size of the swap storage area 302 (that is, the swap area file 302) can be suppressed.

  The reason is that when the size of the unused storage area included in the swap storage area 302 is larger than the area where writing based on the access request is performed, the management unit 11 sets the unused storage area as the write destination. It is because it sets. When an unused storage area included in the swap storage area 302 is divided, the rearrangement unit 14 rearranges the used areas to connect the unused storage areas. Therefore, the swap storage area 302 is used efficiently.

  The present embodiment further has a fourth effect that an increase in load on the information processing apparatus 2 and the storage apparatus 3 due to execution of processing based on the area release command transmitted by the virtual machine 20 can be suppressed. is there.

  The reason is that the release unit 15 stores the location of the release target area until a predetermined condition is satisfied. Then, when the predetermined condition is satisfied, the release unit 15 releases the release target area. As the predetermined condition, for example, it can be set that the load on the information processing apparatus 2 is equal to or lower than a predetermined reference, or the load on the storage apparatus 3 is equal to or lower than a predetermined reference. When these conditions are set as the above-mentioned predetermined conditions, an increase in the load on the information processing apparatus 2 or the storage apparatus 3 can be suppressed.

  The present embodiment has the fifth effect that the first to fourth effects described above can be obtained without modifying the guest OS 21 operating in the virtual machine 20.

  The reason is that the management unit 11 assigns the storage area actually accessed based on whether the address of the access destination by the virtual machine 20 controlled by the guest OS 21 is an address included in the swap area to other storage areas. This is because the storage area is changed.

<Implementation example>
Next, an implementation example of the information processing system 100 based on the first embodiment will be described in detail with reference to the drawings.

  FIG. 12 is a diagram schematically illustrating the function of this implementation example.

  Referring to FIG. 12, the present implementation example includes a guest OS 21, a hypervisor 22 </ b> A, and a disk 30. In FIG. 12, the information processing apparatus 2 that executes the hypervisor 22A is omitted. Further, the virtual machine 20 emulated by the information processing apparatus 2 controlled by the hypervisor 22A and controlled by the guest OS 21 is omitted.

  The guest OS 21 includes an I / O function 101 and an area release function 102.

  The hypervisor 22A includes a swap area confirmation function 201, a virtual disk analysis function 202, an I / O confirmation function 203, a release area management function 204, a swap area deletion function 205, and an area information storage function 206. The area virtue storage function 206 stores a swap area address 251 and a release area list 252.

  The disk 30 includes a thin disk 301 and a swap area file 302.

  Hereinafter, the operation of the virtual machine 20 controlled by the guest OS 21 will be described as the operation of the guest OS 21 or a function provided in the guest OS 21. Furthermore, the operation of the processor of the information processing apparatus 2 controlled by the hypervisor 22A will be described as the operation of the function provided in the hypervisor 22A or the hypervisor 22A.

  First, the correspondence between the components of this implementation example and the components of the first embodiment will be described.

  The guest OS 21 corresponds to the virtual machine 20 in the first embodiment. The hypervisor 22A corresponds to the storage area management device 1 and the virtual machine execution unit 22 in the first embodiment. The disk 30 corresponds to the storage device 3.

  The swap area confirmation function 201 corresponds to the operation detection unit 16 and the securing unit 19. The virtual disk analysis function 202 corresponds to the swap area detection unit 17. The I / O confirmation function 203 corresponds to the request detection unit 10, the management unit 11, and the request execution unit 12. The release area management function 204 corresponds to the relocation unit 14 and the release unit 15. The swap area deletion function 205 corresponds to the operation detection unit 16 and the deletion unit 18. The area information storage function 206 corresponds to the area information storage unit 13.

  FIG. 13 is a block diagram schematically illustrating functions that operate when the virtual machine 20 is activated in the hypervisor 22A. In the drawings from FIG. 13 to FIG. 17 to be described later, the function indicated by the bold line represents the function to operate. When the virtual machine 20 is activated by the hypervisor 22A, the swap area confirmation function 201 opens the thin disk 301. The virtual disk analysis function 202 confirms the logical address of the swap area included in the thin disk 301. The swap area confirmation function 201 records the confirmed logical address in the swap area address 251. The swap area confirmation function 201 further creates a swap area file 302 and a release area list 252.

  FIG. 14 is a block diagram schematically illustrating functions that operate when the virtual machine 20 stops in the hypervisor 22A. When the virtual machine 20 is stopped in the hypervisor 22A, the swap area deletion function 205 determines whether the stop of the virtual machine 20 is due to suspension. The swap area deletion function 205 further checks whether a dump file is stored in the swap area file 302. When the swap area file 302 can be deleted, the swap area deletion function 205 deletes the swap area file 302, the swap area address 251, and the release area list 252.

  FIG. 15 is a block diagram schematically illustrating functions that operate when the guest OS 21 performs I / O. Implementation of I / O or issuance of I / O corresponds to transmission of a write request or a read request in the description of the first embodiment. In this implementation example, the I / O in this case represents an access request (that is, a request command). When the I / O function 101 of the guest OS 21 performs I / O, the I / O confirmation function 203 compares the address of the target area with the swap area address 251 so that the target area of the I / O is the swap area. Determine if there is. The I / O confirmation function 203 issues an I / O to the thin disk 301 when the target area is not included in the swap area. When the target area is included in the swap area and the issued I / O is a read request, the I / O confirmation function 203 reads data from the used area associated with the target area in the swap area file 302. If the target area is included in the swap area and the issued I / O is a write request, control is transferred to the release area management function 204. The release area management function 204 refers to the release area list 252 to determine whether the requested write can fit in the released area. Then, the release area management function 204 determines an appropriate write area in the swap area file 302 based on the determination result. The I / O confirmation function 203 performs writing based on the issued I / O in the determined write area.

  FIG. 16 is a block diagram schematically illustrating a function that operates when the area release function 102 of the guest OS 21 makes an area release request. The I / O confirmation function 203 of the hypervisor 22A receives the area release command transmitted by the area release function 102 of the guest OS 21. When receiving the area release command, the I / O confirmation function 203 transfers control to the release area management function 204. The release area management function 204 ends the process after adding the release area to the release area list 252.

  FIG. 17 is a block diagram schematically illustrating a function that operates when the release area management function 204 reduces the capacity of the swap area file 302. The release area management function 204 refers to the release area list 252. The release area management function 204 deletes data corresponding to the release area in the swap area file 302 based on the release area list 252. Furthermore, the release area management function 204 reduces the size of the swap area file 302 by defragmenting the swap area file 302. In this implementation example, the defragmentation includes reducing the size of the swap area file 302 by excluding the release area from the swap area file 302.

  Next, the operation of this implementation example will be described in detail with reference to the drawings.

  FIG. 8 shows the operation of this implementation example when the virtual machine 20 is activated.

  When the virtual machine 20 is activated (step S101), the swap area confirmation function 201 determines whether the activation of the virtual machine 20 is a return from suspend (step S102). Furthermore, the swap area confirmation function 201 confirms whether the swap area file 302 already exists (step S103). When the activation of the virtual machine 20 is a return from suspend (Yes in step S102), or when the swap area file 302 already exists (Yes in step S103), the hypervisor 22A operates as shown in FIG. Exit. The swap area file 302, swap area address 251, and release area list 252 that are not deleted when the previous virtual machine 20 is stopped are used as they are. If the activation of the virtual machine 20 is not return from suspend (No in step S102), and if the swap area file 302 does not exist (No in step S103), the operation proceeds to step S104. The swap area confirmation function 201 opens the thin disk 301 (step S104). Next, the virtual disk analysis function 202 identifies the address of the swap area included in the thin disk 301 (step S105).

  The swap area confirmation function 201 stores the specified address in the area information storage function 206 as the swap area address 251 (step S107). In addition, the swap area confirmation function 201 creates a swap area file 302 (step S106). Further, the swap area confirmation function 201 creates the release area list 252 (step S108).

  FIG. 9 shows the operation of this implementation example when the virtual machine 20 is stopped.

  When the virtual machine 20 is stopped (step S201), the swap area deletion function 205 determines whether the virtual machine 20 is stopped due to suspension (step S202). The swap area deletion function 205 further determines whether a dump file is stored in the swap area file 302 (step S203). When the virtual machine 20 is stopped by the suspend (Yes in Step S202) and the dump file is stored in the swap area file 302 (Yes in Step S202), the operation illustrated in FIG. If the virtual machine 20 has not been suspended due to suspend (No in step S202), and no dump file is stored in the swap area file 302 (No in step S202), the operation proceeds to step S204 and subsequent steps. In that case, the swap area deletion function 205 deletes the swap area address 251 (step S204). The swap area deletion function 205 further deletes the swap area file 302 (step S205). The swap area deletion function 205 further deletes the release area list 252 (step S206).

  FIG. 10 shows the operation of this implementation example when the guest OS 21 performs I / O.

  When the guest OS 21 performs I / O, the I / O confirmation function 203 of the hypervisor 22A receives the I / O. The I / O confirmation function 203 identifies the issued I / O command type (step S301). The command type corresponds to the type of access request in the description of the first embodiment. When the command type is read or write, the I / O confirmation function 203 confirms the logical address of the target area (step S302). The I / O confirmation function 203 determines whether the target area is included in the swap area by comparing the logical address of the target area with the address stored as the swap area address 251 (step S303). If the target area exists outside the swap area (No in step S303), the I / O confirmation function 203 issues an I / O to the thin disk 301 (step S304). If the target area exists in the swap area (Yes in step S303), and if the I / O command type is read (No in step S305), the operation proceeds to step S306 and step S307. The I / O confirmation function 203 reads data from the swap area file 302 (steps S306 and S307). When the I / O command type is write (Yes in step S305), the I / O confirmation function 203 transfers control to the release area management function 204 to confirm the write target address. The release area management function 204 compares the I / O request size with the released size based on the release area list 252 (step S308). The required size of I / O is the size of the area where writing is performed. The released size is the total size of the release area. If the I / O request size is larger than the released size (Yes in step S308), the release area management function 204 notifies the I / O confirmation function 203 of the end address of the swap area file 302. If the I / O request size is smaller than the released size (No in step S308), the release area management function 204 has a continuous release area having a size equal to or larger than the write request size that is the I / O request size. It is determined whether or not to perform (step S309). When there is no continuous release area having a size equal to or larger than the write request size (No in step S309), the release area management function 204 performs defragmentation (step S310). Then, the release area management function 204 secures a write target area in the release area (step S311). The release area management function 204 notifies the I / O confirmation function 203 of the address of the reserved write target area. The I / O confirmation function 203 writes to the notified address in the swap area file 302 (step S312).

  FIG. 18 is a flowchart illustrating an example of the operation of the storage area management device 1 when the virtual machine 20 transmits an area release command. That is, FIG. 18 shows the operation of the hypervisor 22A when the guest OS 21 issues an area release command. Each step in FIG. 18 and later-described FIG. 19 is the same as the step given the same reference numeral in the operation shown in FIG.

  The operation shown in FIG. 18 will be described as the operation of this implementation example.

  When the guest OS 21 issues an area release command, the I / O confirmation function 203 of the hypervisor 22A receives the issued area release command (step S401). The I / O confirmation function 203 confirms the issued command type. Then, if the command type is an area release command, the I / O confirmation function 203 transfers control to the release area management function 204. The release area management function 204 adds the release target address specified based on the issued area release command to the release area list 252 (step S404). Then, the operation shown in FIG. 18 ends.

  FIG. 19 is a flowchart illustrating an example of an operation of rearranging used areas in the storage area management apparatus 1. That is, FIG. 19 shows an operation in which the release area management function 204 defragments the swap area file 302.

  The release area management function 204 determines whether or not a predetermined condition is satisfied (step S402). For example, the release area management function 204 determines whether the total size of the release target areas is equal to or greater than a threshold based on the release area list 252. When the total size of the release target areas is equal to or larger than the threshold, the release area management function 204 determines whether the access amount to the disk 30 in which the swap area file 302 exists is equal to or smaller than the threshold. The access amount is a value representing the load on the disk 30 measured based on a predetermined standard. When the access amount is equal to or smaller than the threshold (Yes in Step S403), the release area management function 204 releases the release target area in the file system (Step S405). Then, the release area management function 204 defragments the swap area file 302 (step S406). When the total size of the release target areas is equal to or less than the threshold, and when the total size of the release target areas is equal to or greater than the threshold but the I / O amount is equal to or greater than the threshold, the release area management function 204 determines the next determination. Do. In the next determination, the release area management function 204 determines whether the free capacity of the disk 30 in which the swap area file 302 exists is equal to or less than a threshold value. When the free space is equal to or smaller than the threshold, the release area management function 204 determines that it is necessary to rush the area release. Then, the release area management function 204 executes release (step S405) and defragmentation (step S406). The hypervisor 22A periodically performs the operation illustrated in FIG. 19 in the background, for example.

<Second Embodiment>
Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 20 is a block diagram showing the configuration of the storage area control device 1A of this embodiment.

  Referring to FIG. 20, the storage area management device 1A of the present embodiment includes a request detection unit 10 that detects a write request to a swap area in an allocation area 301 that is a storage area allocated to the virtual machine 20, and a write request. In the swap area in which the write is requested, and an area in the swap storage area 302 allocated to the swap area from another storage area not included in the allocation area. A management unit 11 to be associated; and a request execution unit 12 that performs writing based on the write request with respect to a used area that is the area associated with the target area.

  20 is the same as the information processing apparatus 2 shown in FIG. 1 except that the information processing apparatus 2A shown in FIG. 20 includes the storage area control apparatus 1A instead of the storage area control apparatus 1.

  The present embodiment described above has the first effect of the first embodiment. The reason is the same as the reason why the first effect of the first embodiment occurs.

  Can be realized by a computer and a program for controlling the computer, dedicated hardware, or a combination of a program for controlling the computer and the computer and dedicated hardware, respectively.

  FIG. 21 is a diagram illustrating an example of a configuration of a computer 1000 that can implement the storage area management apparatus 1, the storage area management apparatus 1A, the information processing apparatus 2, and the information processing apparatus 2A. Referring to FIG. 21, a computer 1000 includes a processor 1001, a memory 1002, a storage device 1003, and an I / O (Input / Output) interface 1004. The computer 1000 can access the recording medium 1005. The memory 1002 and the storage device 1003 are storage devices such as a RAM (Random Access Memory) and a hard disk, for example. The recording medium 1005 is, for example, a storage device such as a RAM or a hard disk, a ROM (Read Only Memory), or a portable recording medium. The storage device 1003 may be the recording medium 1005. The processor 1001 can read and write data and programs from and to the memory 1002 and the storage device 1003. The processor 1001 can access, for example, the storage apparatus 3 via the I / O interface 1004. The processor 1001 can access the recording medium 1005. The recording medium 1005 stores a program that causes the computer 1000 to operate as the storage area management apparatus 1, the storage area management apparatus 1A, the information processing apparatus 2, or the information processing apparatus 2A.

  The processor 1001 loads a program stored in the recording medium 1005 to cause the computer 1000 to operate as the storage area management apparatus 1, the storage area management apparatus 1A, the information processing apparatus 2, or the information processing apparatus 2A. To do. Then, when the processor 1001 executes the program loaded in the memory 1002, the computer 1000 operates as the storage area management apparatus 1, the storage area management apparatus 1A, the information processing apparatus 2, or the information processing apparatus 2A.

  The request detection unit 10, the management unit 11, the request execution unit 12, the relocation unit 14, the release unit 15, the operation detection unit 16, the swap area detection unit 17, the deletion unit 18, the securing unit 19, and the virtual machine execution unit 22 are, for example, It can be realized by a dedicated program that can be read from a recording medium 1005 that stores the program into the memory 1002 and that can realize the functions of the respective units, and a processor 1001 that executes the program. The area information storage unit 13 can be realized by a memory 1002 included in the computer 1000 or a storage device 1003 such as a hard disk device. Alternatively, the request detection unit 10, the management unit 11, the request execution unit 12, the area information storage unit 13, the rearrangement unit 14, the release unit 15, the operation detection unit 16, the swap area detection unit 17, the deletion unit 18, the securing unit 19, Part or all of the virtual machine execution unit 22 may be realized by a dedicated circuit that implements the function of each unit.

  The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1, 1A Storage area management apparatus 2, 2A Information processing apparatus 3 Storage apparatus 10 Request detection part 11 Management part 12 Request execution part 13 Area information storage part 14 Relocation part 15 Release part 16 Operation | movement detection part 17 Swap area detection part 18 Deletion Part 19 securing part 20 virtual machine 21 guest OS
22 Virtual Machine Execution Unit 22A Hypervisor 30 Disk 100 Information Processing System 101 I / O Function 102 Area Release Function 201 Swap Area Confirmation Function 202 Virtual Disk Analysis Function 203 I / O Confirmation Function 204 Release Area Management Function 205 Swap Area Deletion Function 206 Area information storage function 251 Swap area address 252 Release area list 301 Allocation area (thin disk)
302 Swap storage area (swap area file)
1000 Computer 1001 Processor 1002 Memory 1003 Storage Device 1004 I / O Interface 1005 Recording Medium

Claims (10)

Request detection means for detecting a write request to the swap area of the allocated area, which is a storage area allocated to the virtual machine;
A target area that is requested to be written by the write request in the swap area in which a write request is detected, and an area in the swap storage area that is allocated to the swap area from another storage area that is not included in the allocated area. A management means for associating
Request execution means for performing writing based on the write request to a used area that is the area associated with the target area;
A storage area management device. In the allocation area, when a write request is made to the allocation area, a storage area is allocated to an area where writing is performed by the write request, and a storage area is not allocated to an area where writing is not performed. The storage area management apparatus according to claim 1, wherein the storage area management apparatus is a virtual storage area of a format. In the swap storage area, further comprising area information storage means for storing a release area data value indicating a location of a release area that is an area not associated with the target area,
The storage area according to claim 1 or 2, wherein the management unit specifies a continuous area having a size equal to the target size from the release area, and associates the specified area with the target area as the use area. Management device. When the total size of the release areas is equal to or larger than the target size and there is no continuous release area whose size is equal to or larger than the target size, the continuous release area whose size is equal to or larger than the target size The storage area management device according to claim 1, further comprising a rearrangement unit that moves the used area in the swap storage area so that the used area is generated. The request detection means further detects a release request for requesting release of the target area,
When the predetermined condition is not satisfied, the storage area management device holds the detected release request, and when the predetermined condition is satisfied, the storage area management device stores the release area in the write area for which release is requested by all the held release requests. The apparatus further comprises release means for releasing the association of the associated use area with the write area and updating the release area data value so that the use area for which the association has been released is included in the release area. The storage area management device according to claim 1. The storage area management device according to claim 5, wherein the pre-relocation unit further moves the use area in the swap storage area so that the use area continues when the predetermined condition is satisfied. Operation detecting means for detecting start and stop of the operation of the virtual machine;
When the activation of the virtual machine is detected, swap area detection means for detecting the swap area in the storage area accessed by the virtual machine;
Securing means for allocating the swap storage area having a size corresponding to the detected swap area in the other storage area, and allocating the secured swap storage area to the swap area;
A deletion unit that cancels allocation of the swap area to the swap storage area and securing of the swap storage area in the other storage area when a stop of the operation of the virtual machine is detected;
The storage area management device according to claim 1, comprising: A storage apparatus including the swap storage area and a storage area allocated to the allocation area, and a storage area management apparatus according to any one of claims 1 to 7,
An information processing system comprising virtual machine execution means for executing the virtual machine. Detects a write request to the swap area in the allocated area, which is the storage area allocated to the virtual machine,
A target area that is requested to be written by the write request in the swap area in which a write request is detected, and an area in the swap storage area that is allocated to the swap area from another storage area that is not included in the allocated area. ,
Write based on the write request to the use area, which is the area associated with the target area,
Storage area management method. Computer
Request detection means for detecting a write request to the swap area of the allocated area, which is a storage area allocated to the virtual machine;
A target area that is requested to be written by the write request in the swap area in which a write request is detected, and an area in the swap storage area that is allocated to the swap area from another storage area that is not included in the allocated area. A management means for associating
Request execution means for performing writing based on the write request to a used area that is the area associated with the target area;
Storage area management program to be operated.

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