Storage apparatus and volume management method

Abstract

The storage apparatus comprises a storage unit storing data read/written by the host apparatus, and a control unit controlling writing of the data to the storage unit. The control unit configures one or more pools from the storage unit and divides one of the pools into first pages having an area of a first size and divides the first pages into second pages having the second area, and manages the pages, manages a data storage area of a first volume storing the data by using the first-size area and manages a data storage area of a second volume storing the data by using the second-size area, assigns the first page to the data storage area of the first volume, and assigns the first page in units of the second volume and assigns the second page obtained by dividing the first page to the data storage area of the second volume.

1 . A storage apparatus comprising at least one storage device and a controller, wherein the controller is configured to:
 manage a pool which is provided by storage areas of the at least one storage device;   provide a plurality of volumes;   allocate a first large page with a large page size to one of the volumes from the pool and store first data in a large page size in the allocated first large page; and   allocate a second large page with a large page size to one of the volumes from the pool and store second data in a small page size in a small page in the allocated second large page,   wherein the small page is managed by dividing the large page into units of the small page.   
     
     
         2 . The storage apparatus according to  claim 1 , 
       wherein the controller is further configured to obtain a snapshot of a first volume which is one of the plurality of volumes, 
       wherein the large page stores data written to the first volume, and the small page stores difference data between the first volume and the snapshot volume of the first volume. 
     
     
         3 . The storage apparatus according to  claim 1 , 
       wherein the second large page includes small pages, one of which stores data of one of the plurality of volumes, and another of which stores data of another of the plurality of volumes. 
     
     
         4 . A storage apparatus comprising at least one storage devices and a controller, wherein the controller is configured to:
 manage a pool which is provided by storage areas of the at least one storage device;   provide a first volume and a plurality of second volumes;   allocate a first large page from the pool for a use of the first volume and store data written to the first volume in a large page size in the allocated first large page; and   manage a second large page from the pool for a use of the plurality of second volumes and store data to one of the second volumes in a small page size in a small page included in the second large page,   wherein the small page is managed by dividing the large page into units of the small page.   
     
     
         5 . The storage apparatus according to  claim 4 , 
       wherein the plurality of second volumes are snapshot volumes of the first volume. 
     
     
         6 . The storage apparatus according to  claim 5 , 
       wherein the second large page includes small pages, one of which stores data of a first second volume of the plurality of second volumes and another of which stores data of a second volume of the plurality of second volumes. 
     
     
         7 . The storage apparatus according to  claim 4 , 
       wherein the controller is further configured to, in response to a write access to the first volume, allocate the first large page to the first volume so as to manage the first large page for use of the first volume. 
     
     
         8 . The storage apparatus according to  claim 4 , 
       wherein the controller is further configured to, in response to creation of a snapshot volume, provide one of the second volumes as the snapshot volume of the first volume. 
     
     
         9 . The storage apparatus according to  claim 5 , 
       wherein the controller is further configured to, in response to a write request to a storage area in the first volume to which the first page is allocated, copy data previously stored in the allocated first page in a unit of the second page size to one of the second volumes and store the copied data in the second page included in the first page which is managed for use of the second volume. 
     
     
         10 . A volume management method using a storage apparatus, the storage apparatus comprising at least one storage device and a controller, the controller configured to manage a pool which is provided by storage areas of the at least one storage device and provide a plurality of volumes, 
       the volume management method comprising:
 allocating a first large page with a large page size to one of the volumes from the pool and storing first data in a large page size in the allocated first large page; and 
 allocating a second large page with a large page size to one of the volumes from the pool and storing second data in a small page size in a small page in the allocated second large page, 
 wherein the small page is managed by dividing the large page into units of the small page. 
 
     
     
         11 . The volume management method according to  claim 10 , 
       further comprising obtaining a snapshot of the first volume which is one of the plurality of volumes, 
       wherein the large page stores data written to the first volume, and the small page stores difference data between the first volume and the snapshot volume of the first volume. 
     
     
         12 . The volume management method according to  claim 10 , 
       wherein the second large page includes small pages, one of which stores data of one of the plurality of volumes, and another of which stores data of another of the plurality of volumes. 
     
     
         13 . A volume management method using a storage apparatus comprising at least one storage devices and a controller, the controller configured to manage a pool which is provided by storage areas of the at least one storage devices and provide a first volume and a plurality of second volumes, 
       the volume management method comprising:
 allocating a first large page from the pool for a use of the first volume and storing data written to the first volume in a large page size in the allocated first large page; and 
 manage a second large page from the pool for a use of the plurality of second volumes and storing data to one of the second volumes in a small page size in a small page included in the second large page, 
 wherein the small page is managed by dividing the large page into units of the small page. 
 
     
     
         14 . The volume management method according to  claim 13 , 
       wherein the plurality of second volumes are snapshot volumes of the first volume. 
     
     
         15 . The volume management method according to  claim 14 , 
       wherein the second large page includes small pages, one of which stores data of a first second volume of the plurality of second volumes, and another of which stores data of a second volume of the plurality of second volumes. 
     
     
         16 . The volume management method according to  claim 13 , 
       further comprising, in response to a write access to the first volume, allocating the first large page to the first volume so as to manage the first large page for use of the first volume. 
     
     
         17 . The volume management method according to  claim 13 , 
       further comprising, in response to creation of a snapshot volume, providing one of the second volumes as the snapshot volume of the first volume. 
     
     
         18 . The volume management method according to  claim 14 , 
       further comprising, in response to a write request to a storage area in the first volume to which the first page is allocated, copying data previously stored in the allocated first page in a unit of the second page size to one of the second volumes and storing the copied data in the second page included in the first page which is managed for use of the second volume.