Abstract: A storage system connected to a computer and a management computer, includes storage devices accessed by the computer, and a control unit for controlling the storage devices. A first-type logical device corresponding to a storage area set in at least one of the storage devices and a second-type logical device that is a virtual storage area are provided. The control unit sets at least two of the first-type logical devices different in a characteristic as storage areas included in a storage pool through mapping. The first-type logical device stores data by allocating a storage area of the second-type logical device to a storage area of the first-type logical device mapped to the storage pool. The characteristic of the second-type logical device can be changed by changing the allocated storage area of the second-type logical device to a storage area of another first-type logical device.

Abstract: A storage system for storage of data written from a computer, and when a write request of data to a first logical volume is received, the data on request is stored into the first logical volume. When a first-generation snapshot creation request is received, the data stored in the first logical volume at the time of receiving the first-generation snapshot creation request is written into a pool region as data corresponding to a first-generation snapshot, and when a second-generation snapshot creation request is received, any portion of the data updated after the first-generation snapshot creation request is received but before the second-generation snapshot creation request is issued is read from the first logical volume for writing into the pool region. Such a storage system favorably implements snapshot backup with no dependency with a positive volume in terms of performance and failure, and with high capacity efficiency.

Abstract: A second storage maps a migration source volume to a virtual volume of a migration destination volume according to storage virtualization technology. A host system including a host switches an access path from an access path to the migration source volume to an access path to the migration destination volume. The second storage executes copy processing of migrating, from the migration source volume to the migration destination volume, data in an assigned area of a virtual volume according to thin provisioning of the migration source volume based on the information contained in the first thin provisioning information in the first storage, and copying that data from the migration destination volume to a virtual volume according to thin provisioning of a copy destination volume in the second storage. The second storage associates the virtual volume of the copy destination volume with the migration destination volume in substitute for the original virtual volume.

Abstract: The present invention transfers replication logical volumes between and among storage control units in a storage system comprising a plurality of storage control units. To transfer replication logical volumes from a storage control unit to a storage control unit, a virtualization device sets a path to the storage control unit. The storage control unit then prepares a differential bitmap in order to receive access requests. When the preparation is completed, the virtualization device makes access requests to the storage control unit. The storage control unit then hands over the access requests to the storage control unit. Subsequently, the storage control unit performs a process so that the access requests are reflected in a disk device and performs an emergency destage of storing data in a cache memory into disk device. When the emergency destage is ended, the storage control unit connects to an external storage control unit and hands over access requests to the external storage control unit.

Abstract: The present invention allows distribution of load generated by a single VOL to multiple processor units, by dividing the VOL into a plurality of smaller fractions called sub-VOL and distributing their ownership to multiple processor units. The division of a VOL is performed by dividing the control information of the VOL for plurality of sub-VOLs and (A) assigning VOL ownership to a processor unit for processing the tasks that are related to complete VOL (e.g. VOL RESERVE command) and (B) assigning ownership of each sub-VOL to different processor units for processing tasks that are specific to that sub-VOL (e.g. Read/Write commands). Thus the load on a singular sub-VOL owner processor unit becomes only a fraction of the total load generated by the VOL. The present invention helps in achieving a relatively even distribution of load among processor units.

Abstract: A storage system connected to a computer and a management computer, includes storage devices accessed by the computer, and a control unit for controlling the storage devices. A first-type logical device corresponding to a storage area set in at least one of the storage devices and a second-type logical device that is a virtual storage area are provided. The control unit sets at least two of the first-type logical devices different in a characteristic as storage areas included in a storage pool through mapping. The first-type logical device stores data by allocating a storage area of the second-type logical device to a storage area of the first-type logical device mapped to the storage pool. The characteristic of the second-type logical device can be changed by changing the allocated storage area of the second-type logical device to a storage area of another first-type logical device.

Abstract: When a computer 10 receives a request from the client computer 30 to access snapshot files, the target device to be used is identified. The computer 10 makes a request to the identified target device TD for attachment of the logical device LDEV that stores the snapshot files for which access is requested. When the computer 10 receives notification that the attachment has ended from the storage device system 20, the identified target device is mounted on the directory in which the snapshot files are stored.

Abstract: A second storage maps a migration source volume to a virtual volume of a migration destination volume according to storage virtualization technology. A host system including a host switches an access path from an access path to the migration source volume to an access path to the migration destination volume. The second storage executes copy processing of migrating, from the migration source volume to the migration destination volume, data in an assigned area of a virtual volume according to thin provisioning of the migration source volume based on the information contained in the first thin provisioning information in the first storage, and copying that data from the migration destination volume to a virtual volume according to thin provisioning of a copy destination volume in the second storage. The second storage associates the virtual volume of the copy destination volume with the migration destination volume in substitute for the original virtual volume.

Abstract: There are a plurality of storage apparatuses including a first storage apparatus and a second storage apparatus. The first storage apparatus has a virtual volume composed of a plurality of virtual segments. At least the second storage apparatus has a pool composed of a plurality of real pages (real storage areas). The plurality of storage apparatuses each manage one or more pools including at least the pool in the second storage apparatus as one virtual pool. The virtual pool is composed of a plurality of virtual pages, and each virtual page corresponds to any of the real pages. The first storage apparatus receives a write command that specifies an address belonging to an unallocated virtual segment to which no virtual page is allocated, allocates a free virtual page from the virtual pool to the unallocated virtual segment, and writes data accompanying the write command to the real page corresponding to the allocated virtual page.

Abstract: A storage system includes a first storage apparatus and a second storage apparatus. The first storage apparatus includes a capacity pool that is partitioned into multiple pool pages and includes a storage area of an external logical volume provided by at least one storage apparatus. The second storage apparatus provides first virtual volume which is a virtual logical volume comprising multiple first virtual areas. In a case of receiving a write request from the computer to a virtual area in the first virtual volume to which a page is not allocated, an unallocated pool page of the external logical volume is allocated to the virtual area. An authority to allocate the unallocated pool page of the external logical volume is assigned to the first storage apparatus.

Abstract: The respective data fragments stored in each page assigned to the respective virtual areas of the virtual volume are copied to the logical volume, and information representing the respective copy source pages corresponding with information representing the respective virtual areas in the mapping information that indicates which storage area corresponds with which virtual area is updated to information representing the respective copy destination storage areas of the data fragments stored in the respective copy source pages and copies the updated mapping information to the logical volume which constitutes the data fragment copy destination.

Abstract: A storage system enables a core storage apparatus to execute processing requiring securing of data consistency, while providing high write performance to a host computer. A storage system includes an edge storage apparatus 20 configured to communicate with a host computer 10 and including a cache memory 25, and a core storage apparatus 30 that communicates with the edge storage apparatus 20 and perform I/O processing on a storage device 39. When receiving a write request from the host computer 10, the edge storage apparatus 20 processes the write request by writeback. When about to execute storage function control processing, on condition that data consistency is be secured, such as pair split processing of a local copy function, the core storage apparatus 30 requests the edge storage apparatus 20 to perform forced destage of dirty data in the cache memory 25 and then executes the storage function control processing after the completion of the forced destage.

Abstract: The present invention creates a pool comprising tiers corresponding to the performance of logical volumes. A first storage apparatus either acquires or measures the performance of multiple external pool volumes of an external storage (S1711 through S1714), and creates a pool volume group based on the performance of the external pool volumes (S1715, S1716). The rank order of a tier is decided in accordance with the performance of each pool volume group (S1717, S1718). This makes it possible to relatively easily create a pool comprising multiple appropriate tiers that are suited to the current situation.

Abstract: Provided is a computer system capable equalizing the storage capacity immediately and reliably to multiple real logical areas dynamically providing storage capacity to virtual logical areas. This computer system is characterized by, during the course of executing an operation of dynamically allocating a storage area to a virtual volume in response to an access from a host system, detecting an occasion where balance of a storage capacity among a plurality of logical areas is disrupted; and subsequently moving the storage area among a plurality of logical areas to maintain balance of the storage capacity.

Abstract: There is a journal area and one or more logical volumes comprising a first logical volume. The journal area is a storage area in which is stored a journal data element, which is a data element that is stored in any storage area of a plurality of storage areas configuring a logical volume, or a data element that is written to the storage area. A controller has a size receiver that receives a write unit size, which is the size of a write data element received from a computer, and a size setting unit that sets the received write unit size in a memory for one or more logical volumes. The size of a journal data element stored in a journal area based on the set write unit size is the write unit size.

Abstract: A storage system including: a controller; and, a plurality of physical storage devices coupled to the controller and constituting a RAID group; wherein the controller provides one or more logical volumes belonging to the RAID group, each of the one or more logical volumes having a plurality of storage areas; and one or more virtual volumes, wherein, when receiving a write request to a virtual volume of the one or more virtual volumes, the controller is configured to: allocate a storage area in a logical volume to the virtual volume, as an allocated storage area, where reliability of the storage area is used as a criterion in a selection of the storage area for allocation to the virtual volume; and write data to the allocated storage area, wherein, the controller is configured to selectively perform a RAID allocation process to a storage area allocated to a virtual volume.

Abstract: In general, a DRAM is used as a cache memory, and when attempting to expand the capacity of the cache memory to increase the hit ratio, the DRAM is required to be physically augmented, which is not a simple task. Consequently, a storage system uses a page, which conforms to a capacity virtualization function (for example, a page allocatable to a logical volume in accordance with Thin Provisioning), as a cache area. This makes it possible to dynamically increase and decrease the cache capacity.

Abstract: A virtual storage system is equipped with a plurality of storage systems and a virtualization device for virtualizing the plurality of storage systems logically into a single storage resource provided to a host computer. When one of the storage systems receives a command from the host computer, in the event that the storage system itself is not in possession of a function corresponding to the command, the storage system retrieves a storage system in possession of a function corresponding to the command and transfers this command to the storage system in possession of the function corresponding to the command.

Abstract: Availability of an information system including a storage apparatus and a host computer is improved. A host system includes a first storage apparatus provided with a first volume for storing data, and a second storage apparatus for storing the data sent from the first storage apparatus. In case of a failure occurring in the first storage apparatus, the host sends the data to be sent to the first storage apparatus to the second storage apparatus.

Abstract: Provided is a storage system capable of starting/stopping a disk drive. At the time of allocating a logical device, it is judged, based on attributes including a purpose of the logical device, whether or not control can be performed in terms of start/stop of an allocation target disk drive to determine an allocation destination disk drive. Further, in the case where access to a specific logical device is stopped due to release of a path definition or other such cause, it is judged whether or not a disk drive corresponding to the logical device can be stopped. When it is judged that the disk drive can be stopped, the disk drive is stopped. When it is judged that the disk drive cannot be stopped, the logical device is migrated to another disk drive that can be stopped, a migration destination disk drive is stopped.