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: A switch connected to a network system including a computer and a storage apparatus: controlling read/write request from the computer to the storage apparatus and controlling to store journal data in the storage apparatus; wherein the storage apparatus includes a first storage area for storing data to be used by the computer and a second storage area for storing journal data including write data and first update log information corresponding to the write data when there is a write request from the computer for writing data in the first storage area; wherein when the switch detects an event of status change related to the network system, the switch marks a first point of time corresponding to the event as a recovery request point, and creates second update log information corresponding to the recovery request point.

Abstract: There is provided a storage subsystem having a virtual volume and a page volume which has a page physical area allocated to the virtual volume. The storage subsystem divides an address space of the virtual volume into a plurality of pages, classifies each of the pages into one of a plurality of states including at least a first state and a second state, and further divide a page which is classified into the second state into a plurality of segments to managed the page classified into the second state. The first state is a state in which a page physical area is allocated to the page from the page volume, and the write data is stored in the page physical area. The second state is a state in which the predetermined pattern data and the segment are managed, in the memory, by correlating with each other.

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: 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: This invention provides a storage system to store data used by computers. A storage system coupled to a computer and a management apparatus, includes storage devices accessed by the computer and a control unit that controls the storage devices, in which the control unit performs the following operations: setting, in the storage devices, a first virtual device including a first logical device; setting a second virtual device which including a second logical device, which is a virtual volume accessed by the computer; allocating an address of the first logical device to the second logical device; and changing the allocation to change storage areas of the virtual volume.

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 control system comprises a storage resource and a controller. If the controller receives a write command which specifies an address belonging to a virtual volume, to the area belonging to the address, unassigned pages in a pool which is a storage area based on a plurality of media types of physical storage media and which is divided into a plurality of pages are supposed to be assigned. The storage control system comprises a plurality of management entries which are a plurality of entries for page management information which is the information related to the pages. The plurality of management entries include two or more page entries and two or more statistical entries. A statistical entry about a certain media type corresponds to M pages based on the storage media of the certain media type (M is an integral number which is 2 or larger). The statistical entry corresponding to the M pages comprises the information related to the I/O performance value for those M pages.

Abstract: The storage system includes a first storage system and a second storage system. The first storage system, which is coupled to a computer and the second storage system, includes a first storage control device and a plurality of first storage units. The second storage system includes a plurality of second storage units. The first storage control device provides the computer with a logical unit assigned to at least one of the second storage units, receives a first access request from the computer and sends a second access request to one of plurality of the second storage units, obtains performance information relating to the second access request, and moves data stored in at least one of the plurality of second storage units to at least one of the first storage units according to the performance information.

Abstract: Availability of an information system including a storage system that performs remote copy between two or more storage apparatuses and a host computer using such storage system is improved. A third storage apparatus including a third volume is coupled to a first storage apparatus, a fourth storage apparatus including a fourth volume is coupled to a second storage apparatus, the first and third storage apparatuses perform remote copy of copying data stored in a first volume to the third volume, the first and second storage apparatuses perform remote copy of copying data stored in the first volume to a second volume, and the third and fourth storage apparatuses perform remote copy of copying data stored in the third volume to the fourth volume.

Abstract: If a monitor measurement cycle is set as a long cycle, promotion in a short cycle cannot be performed; and even if the number of I/Os is very large in response to fluctuations of the number of I/Os in several minutes to several hours of normal work, pages will be promoted after waiting for several weeks. As a result, I/Os which could have normally accepted by an upper tier will be accepted by a lower tier, which results in a problem of worsening the performance efficiency. A monitoring system capable of preventing demotion due to temporary reduction of the number of I/Os for specific pages from a viewpoint of a long cycle and enabling prompt promotion in response to an increase of the number of U/Os for 3 the specific pages is realized. A load index value defined from a viewpoint of a long cycle and a load index value defined from a viewpoint of a short cycle are updated based on the number of I/Os which is counted cyclically for each storage area.

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 path is formed between a host computer and storage apparatuses without depending on the configuration of the host computer and a network and a plurality of volumes having a copy function are migrated between storage apparatuses while keeping the latest data.

Abstract: For at least one of storage unit, processor and cache memory which are I/O process-participating devices related to I/O command process, when a load of one or more I/O process-participating devices or a part thereof is a low load equal to or less than a predetermined threshold value, a processing related to a state of one or more of the I/O process-participating devices or a part thereof is redirected to another one or more I/O process-participating devices or a part thereof, and the state of the one or more I/O process-participating devices or a part thereof is shifted to a power-saving state.

Abstract: A computer system having a first storage system which includes a first logical volume and a second logical volume, wherein the second logical volume stores a first differential data item representing a differential between data that was stored in the first logical volume at a first time instant and data that was stored in the first logical volume at a second time instant being later than the first time instant, and a second storage system which includes a third logical volume. The first storage system transmits the first differential data item to the second storage system, the second storage system stores the first differential data item into the third logical volume, the first storage system deletes the first differential data item from the second logical volume, and the computer system retains management information set for associating the first logical volume with the third logical volume storing therein the first differential data item.

Abstract: This invention provides a storage system to store data used by computers. A storage system coupled to a computer and a management apparatus, includes storage devices accessed by the computer and a control unit that controls the storage devices, in which the control unit performs the following operations: setting, in the storage devices, a first virtual device including a first logical device; setting a second virtual device which including a second logical device, which is a virtual volume accessed by the computer; allocating an address of the first logical device to the second logical device; and changing the allocation to change storage areas of the virtual volume.

Abstract: A computer system includes a first volume that is read and written from a first computer and in which write data is written, a second volume that stores journal data in the first volume with the journal data delimited at each predetermined point, a third volume as a virtual volume, a virtual-volume creating unit that creates, when a backup instruction for the first volume at a predetermined point is received, the third volume from which a second computer can read the journal data and in which the second computer can write the journal data, a mapping unit that maps the journal data to the third volume, and a backup unit that transfers the write data to a storage device via the second computer or transfers, through the third volume to which the journal data is mapped by the mapping unit, the journal data to the storage device via the second computer and backs up the write data and the journal data.

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: There is provided a storage subsystem having a virtual volume and a page volume which has a page physical area allocated to the virtual volume. The storage subsystem divides an address space of the virtual volume into a plurality of pages, classifies each of the pages into one of a plurality of states including at least a first state and a second state, and further divide a page which is classified into the second state into a plurality of segments to managed the page classified into the second state. The first state is a state in which a page physical area is allocated to the page from the page volume, and the write data is stored in the page physical area. The second state is a state in which the predetermined pattern data and the segment are managed, in the memory, by correlating with each other.

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.