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 a system where a first storage system and a second storage system are connected to a third storage system, when the first storage system virtualizes and provides a device in the third storage system as a device in its own storage system, update data stored in a cache in the first storage system is written into the device of the third storage system to be reflected, attributes of the device are transferred to the second storage system, and the second storage system virtualizes the device of the third storage system as a device of its own storage system.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

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 data up to a point of time whereat failure has occurred will be restored at high speed at a remote site without imposing any burden on a host. The first storage system on the master side processes an I/O request from the host, and as a result of I/O processing to the second storage system on the remote side, transmits the update data. The second storage system retains data received from the first storage system as update log data. The host transmits a command for settling a state of an application to the first storage system as data, and the first storage system transmits the data to the second storage system. The host and the second storage system both retain an identifier corresponding to the command, and relate the identifier to the log data. Thereby, the host designates the identifier at any given time, whereby the second storage system restores the data at any given time.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

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: A storage controller calculates an access frequency of each logical disk; that is selects a first logical disk device of which the access frequency exceeds a first predetermined value, the first logical disk device being allocated to a first physical disk device; selects a second logical disk device which has the access frequency equal to or less than a second predetermined value, the second logical disk device being allocated to a second physical disk device; and reallocates the first and second logical device; and reallocates the first and second logical devices to the second and the first physical disk device, respectively.

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: Availability of an information system including a storage apparatus and a computer is improved. First and second storage apparatuses execute remote copy of copying data written into a first primary volume from the computer to a second primary volume, at least one of the first and second storage apparatuses executes local copy of copying the data written into the first or second primary volume in a self-storage apparatus to the corresponding first or second secondary volume, and the computer switches the destination of a write request of the data from the first storage apparatus to the second storage apparatus in case of a failure occurring in the first storage apparatus.

Abstract: The temporary area capacity required to be secured with respect to the whole permanent area is calculated in accordance with the capacity and access frequency of a host computer data permanent area of a disk device contained in the storage system and a disk device of an external storage device that is managed by a storage virtualization function of this storage system. The nonvolatile memory is defined as the temporary area and is used to temporarily store host computer data when a data I/O from the host computer is processed. The required capacity of the temporary area is re-calculated in accordance with an event such as a configuration change in the external storage system.

Abstract: Availability of an information system including a storage apparatus and a computer is improved. First and second storage apparatuses execute remote copy of copying data written into a first primary volume from the computer to a second primary volume, at least one of the first and second storage apparatuses executes local copy of copying the data written into the first or second primary volume in a self-storage apparatus to the corresponding first or second secondary volume, and the computer switches the destination of a write request of the data from the first storage apparatus to the second storage apparatus in case of a failure occurring in the first storage apparatus.

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 storage system includes a storage subsystem including a plurality of storage units and a storage control device coupled to a computer and the storage subsystem, the storage control device providing the host computer with a logical unit assigned to a storage unit of the storage subsystem. The storage control device receives a first access request from the computer to the logical unit and sends a second access request to the storage unit of the storage subsystem according to a relation between the storage unit of the storage subsystem and the logical unit assigned to the storage unit. Performance information relating to the second access request by the storage control device is obtained so that the storage control device determines performance relating to the logical unit assigned to the storage unit of the storage subsystem.

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 storage controller calculates an access frequency of each logical disk; that is selects a first logical disk device of which the access frequency exceeds a first predetermined value, the first logical disk device being allocated to a first physical disk device; selects a second logical disk device which has the access frequency equal to or less than a second predetermined value, the second logical disk device being allocated to a second physical disk device; and reallocates the first and second logical device; and reallocates the first and second logical devices to the second and the first physical disk device, respectively.

Abstract: The temporary area capacity required to be secured with respect to the whole permanent area is calculated in accordance with the capacity and access frequency of a host computer data permanent area of a disk device contained in the storage system and a disk device of an external storage device that is managed by a storage virtualization function of this storage system. The nonvolatile memory is defined as the temporary area and is used to temporarily store host computer data when a data I/O from the host computer is processed. The required capacity of the temporary area is re-calculated in accordance with an event such as a configuration change in the external storage system.

Abstract: The storage system is coupled to a computer and includes a plurality of physical storages being used to configure a first logical storage and a second logical storage, a control unit receiving a read request and a write request from the computer; and a cache memory storing data which is sent to the computer. The control unit determines whether a request from the computer is a write request or a read request. If it is a read request, the control unit reads data from the cache memory or at least one of the plurality of physical storages based on the read request. If it is a write request, the control unit determines whether destination of the write request is the first logical storage.

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: Access to a plurality of logical devices is enabled regardless of the number of ports provided in a storage system and the number of logical devices that can be allocated to a single port, thereby improving the usability of the logical devices. A storage system comprises a plurality of logical devices, a target device which is the object of access from a computer, and a juke box system for allocating one of the plurality of logical devices to the target device. The juke box system changes the logical device that is allocated to the target device in accordance with a request from the computer.