Abstract: A flash memory storage system has a plurality of flash memory devices comprising a plurality of flash memories, and a controller having an I/O processing control unit for accessing a flash memory device specified by a designated access destination in an I/O request received from an external device from among the plurality of flash memory devices. A parity group can be configured of flash memory devices having identical internal configuration.

Abstract: A migration destination storage creates an expansion device for virtualizing a migration source logical unit. A host computer accesses an external volume by way of an access path of a migration destination logical unit, a migration destination storage, a migration source storage, and an external volume. After destaging all dirty data accumulated in the disk cache of the migration source storage to the external volume, an expansion device for virtualizing the external volume is mapped to the migration destination logical unit.

Abstract: The present invention efficiently changes a volume size while maintaining a copy pair as-is. A PVOL and a SVOL #1 are in a pair state and are synchronized. The PVOL and a SVOL #2 are in a restore state. Upon instruction of expansion of the size of the PVOL, the size of a copy-destination SVOL #1 is first expanded, the size of the PVOL is then expanded, and the size of the SVOL #2 is lastly expanded. In the case of a PSUS state, only the size of the PVOL is expanded, and the size of the SVOL is left as-is.

Abstract: A flash memory storage system has a plurality of flash memory devices comprising a plurality of flash memories, and a controller having an I/O processing control unit for accessing a flash memory device specified by a designated access destination in an I/O request received from an external device from among the plurality of flash memory devices. A parity group can be configured of flash memory devices having identical internal configuration.

Abstract: Provided is a computer system including: a host computer; a first storage system connected to the host computer; and a second storage system connected to the first storage system; in which the first storage system sets a first logical volume recognized by the host computer as a logical storage area; the first logical volume includes a plurality of first storage areas; a first real storage area on the first disk drive is allocated to at least one of the first storage areas. In the computer system, the second storage system sets a second logical volume corresponding to the first logical volume, and the first storage system transmits data stored in the first storage area allocated to the first storage area to the second storage system when the first real storage area is allocated to the first storage area.

Abstract: An externally-connected volume of a main storage is correlated to an AOU volume inside of an external storage. The AOU volume is allocated with a not-yet-used page in a pool in accordance with data writing. When a command is issued to the externally-connected volume for formatting or others, a first controller in the main storage converts the command into a format command or an area deallocation command with respect to the AOU volume in the external storage. As such, the external AOU volume is subjected to a write process in its entirety, thereby being able to prevent any unnecessary page allocation. With such a configuration, the storage system of the present invention can use pages in the pool with good efficiency.

Abstract: One code (a compressed redundant code) is created based on a plurality of first redundant codes, each created on the basis of a plurality of data units, and this compressed redundant code is written to a nonvolatile storage area. This compressed redundant code is used to restore either a data element constituting a multiple-failure data, or a first redundant code corresponding to the multiple-failure data, which is stored in an unreadable sub-storage area of a partially failed storage device, and to restore the data element constituting the multiple-failure data which is stored in a sub-storage area of a completely failed storage device, based on the restored either data element or first redundant code, and either another data element constituting the multiple-failure data or the first redundant code corresponding to the multiple-failure data.

Abstract: An externally-connected volume of a main storage is correlated to an AOU volume inside of an external storage. The AOU volume is allocated with a not-yet-used page in a pool in accordance with data writing. When a command is issued to the externally-connected volume for formatting or others, a first controller in the main storage converts the command into a format command or an area deallocation command with respect to the AOU volume in the external storage. As such, the external AOU volume is subjected to a write process in its entirety, thereby being able to prevent any unnecessary page allocation. With such a configuration, the storage system of the present invention can use pages in the pool with good efficiency.

Abstract: A migration destination storage creates an expansion device for virtualizing a migration source logical unit. A host computer accesses an external volume by way of an access path of a migration destination logical unit, a migration destination storage, a migration source storage, and an external volume. After destaging all dirty data accumulated in the disk cache of the migration source storage to the external volume, an expansion device for virtualizing the external volume is mapped to the migration destination logical unit.

Abstract: In the storage controller of the present invention, different difference bitmaps are used for predetermined sections respectively, whereby the difference between the primary volume and the base volume is managed for each section, and the data are protected efficiently. The difference between the primary volume and the base volume is managed by using the difference bitmaps that are different for the respective sections. The journal data after a lapse of the targeted protection period are written to the base volume and then discarded. At the time of recovery, the difference bitmaps are merged to create a new difference bitmap, and the difference is copied from the base volume to the primary volume. Thereafter, the journal data up to the designated restoration point are written to the primary volume.

Abstract: A storage group configured by a plurality of storage devices is configured by a plurality of storage sub-groups, and the respective storage sub-groups are configured from two or more storage devices. A sub-group storage area, which is the storage area of the respective storage sub-groups, is configured by a plurality of rows of sub-storage areas. A data set, which is configured by a plurality of data elements configuring a data unit, and a second redundancy code created on the basis of this data unit, is written to a row of sub-storage areas, a compressed redundancy code is created on the basis of two or more first redundancy codes respectively created based on two or more data units of two or more storage sub-groups, and this compressed redundancy code is written to a nonvolatile storage area that differs from the above-mentioned two or more storage sub-groups.

Abstract: One code (a compressed redundant code) is created based on a plurality of first redundant codes, each created on the basis of a plurality of data units, and this compressed redundant code is written to a nonvolatile storage area. This compressed redundant code is used to restore either a data element constituting a multiple-failure data, or a first redundant code corresponding to the multiple-failure data, which is stored in an unreadable sub-storage area of a partially failed storage device, and to restore the data element constituting the multiple-failure data which is stored in a sub-storage area of a completely failed storage device, based on the restored either data element or first redundant code, and either another data element constituting the multiple-failure data or the first redundant code corresponding to the multiple-failure data.

Abstract: Provided are a backup system and a backup method for backing up data written by a host into a logical volume provided by a storage system, wherein an update location in the logical volume updated by the host is managed, and the storage system is controlled to selectively back up the data written into the update location in the logical volume based on the management result of the update location. It is thereby possible to ensure a fast data read speed in the backup of raw volumes and an easy multiplatform backup, whereby a backup system and a backup method capable of performing backup efficiently are realized.

Abstract: A migration destination storage creates an expansion device for virtualizing a migration source logical unit. A host computer accesses an external volume by way of an access path of a migration destination logical unit, a migration destination storage, a migration source storage, and an external volume. After destaging all dirty data accumulated in the disk cache of the migration source storage to the external volume, an expansion device for virtualizing the external volume is mapped to the migration destination logical unit.

Abstract: A storage system is utilized to its fullest storage capacity by setting a write inhibitive attribute to a desired storage area of the storage system. The storage system has a logical volume in which data is stored and a control device which controls access to the data stored in the logical volume. A first area of a desired size is set in the logical volume, and an access control attribute is set to the first area. In response to a request made by a computer to perform access to the logical volume, the control device notifies the computer that the control device does not perform the access when an area designated by the access request contains at least a part of the first area and the access control attribute set to the first area inhibits the type of the access requested.

Abstract: A storage group configured by a plurality of storage devices is configured by a plurality of storage sub-groups, and the respective storage sub-groups are configured from two or more storage devices. A sub-group storage area, which is the storage area of the respective storage sub-groups, is configured by a plurality of rows of sub-storage areas. A data set, which is configured by a plurality of data elements configuring a data unit, and a second redundancy code created on the basis of this data unit, is written to a row of sub-storage areas, a compressed redundancy code is created on the basis of two or more first redundancy codes respectively created based on two or more data units of two or more storage sub-groups, and this compressed redundancy code is written to a nonvolatile storage area that differs from the above-mentioned two or more storage sub-groups.

Abstract: A flash memory storage system has a plurality of flash memory devices comprising a plurality of flash memories, and a controller having an I/O processing control unit for accessing a flash memory device specified by a designated access destination in an I/O request received from an external device from among the plurality of flash memory devices. A parity group can be configured of flash memory devices having identical internal configuration.

Abstract: A storage apparatus conducts, in a protection period, data protection processing for protecting, in a third logical volume, data stored in a first logical volume by using backup data stored in a second logical volume, and suspends the data protection processing in a no-protection period, during which backup relative to the second logical volume is suspended, in the protection period. Then, upon receiving an external order for restoring the first logical volume to its state as of at a time not in the no-protection period within the protection period, the storage apparatus restores the first logical volume to its state as of at a time of the order by using the data backed up in the second logical volume and the data protected in the third logical volume.

Abstract: A migration destination storage creates an expansion device for virtualizing a migration source logical unit. A host computer accesses an external volume by way of an access path of a migration destination logical unit, a migration destination storage, a migration source storage, and an external volume. After destaging all dirty data accumulated in the disk cache of the migration source storage to the external volume, an expansion device for virtualizing the external volume is mapped to the migration destination logical unit.

Abstract: A flash memory storage system has a plurality of flash memory devices comprising a plurality of flash memories, and a controller having an I/O processing control unit for accessing a flash memory device specified by a designated access destination in an I/O request received from an external device from among the plurality of flash memory devices. A parity group can be configured of flash memory devices having identical internal configuration.