Abstract: According to the present invention, each of a plurality of LUs existing on a storage control system 200 is divided into a plurality of chunks. A PVOL is comprised of only FC-chunks, but an SVOL is comprised of both FC-chunks and SATA-chunks. To each of the plurality of SVOL-chunks corresponding to the plurality of PVOL-chunks respectively, either an FC-chunk or SATA-chunk selected from a plurality of pool chunks is dynamically corresponded based on the update frequency of the sub-data of the corresponding PVOL chunk. Specifically, if an SVOL-SATA-chunk is corresponded to the PVOL-chunk of which the data update frequency is high, for example, the pool FC-chunk is corresponded as a sub-data swap destination in that SVOL-SATA-chunk.

Abstract: A journal write unit writes journal data into a third storage device. The journal data includes an identifier of a logical volume in a first storage device into which data has been written, information of a location in which the data is stored in the logical volume, update time which is current time acquired from a timing mechanism, and the data. A second write unit refers to update time of the journal data stored in the third storage device, selects journal data for which a difference between current time acquired from the timing mechanism and the update time is longer than a detection time stored in the third storage device, and writes the data into a place indicated by the location information, in a logical volume in the second storage device in the order of update time in the selected journal data.

Abstract: In a structure where first and second storage devices structure a mirrored pair, at a first time, an updating process to the second storage device is stopped, and management using first and second update-management tables is started. At a second time on or after the first time, management of the first update-management table is started from a non-updated state, and data of the second storage device, stored in the data blocks indicated by the second update-management table as being updated, is copied to a backup medium. At a third time after the second time, data of the first storage device, stored in the data blocks indicated by the second update-management table as being updated, is copied to data blocks of the second storage device corresponding to the data blocks of the first storage device.

Abstract: A method of selecting logical volumes that are the targets for data migration to equilibrate the load on a system, based on the accessing data of the physical drives and logical drives under the disk array controllers, without increasing the load of the disk array controller. An external manager communicates with two or more disk array controllers, gathers and manages the access data and the configuration data relating to the physical drives and logical volumes of each disk array controller, and prepares an optimum data migration instruction to equilibrate the access load.

Abstract: The present invention shortens service termination times and permits rapid transfers. A file tree with the same structure as that of the file tree of a first NAS is formed in a second NAS beforehand. File data is not transferred to the tree. The second NAS saves an association between a file descriptor fd1 managed by the first NAS and fd2 managed by the second NAS. Services for a client are restarted when the transfer of the tree structure is complete. When the client requests access to a desired file by designating fd2, the second NAS converts fd2 to fd1 and requests file data from the first NAS. When the first NAS reads the file data, the second NAS stores the file data in a predetermined location and supplies the file data to the client. In cases where the client desires file access once again, the second NAS reads the transferred file data and supplies same to the client.

Abstract: A method of selecting logical volumes that are the targets for data migration to equilibrate the load on a system, based on the accessing data of the physical drives and logical drives under the disk array controllers, without increasing the load of the disk array controller. An external manager communicates with two or more disk array controllers, gathers and manages the access data and the configuration data relating to the physical drives and logical volumes of each disk array controller, and prepares an optimum data migration instruction to equilibrate the access load.

Abstract: A storage control system comprises a plurality of controllers, each of the controllers receiving a data-input/output request inputted via an external communication path and sending a data-input/output command to storage means; and an internal communication path through which the controllers carry out the data-input/output command and data input/output. Each of the controllers comprises means for sending its own operational information towards other ones of the controllers via the internal communication path. The storage control system further comprises means for monitoring an operational state of each of the controllers based on the operational information sent from the sending means of the controllers.

Abstract: According to the present invention, each of a plurality of LUs existing on a storage control system 200 is divided into a plurality of chunks. A PVOL is comprised of only FC-chunks, but an SVOL is comprised of both FC-chunks and SATA-chunks. To each of the plurality of SVOL-chunks corresponding to the plurality of PVOL-chunks respectively, either an FC-chunk or SATA-chunk selected from a plurality of pool chunks is dynamically corresponded based on the update frequency of the sub-data of the corresponding PVOL chunk. Specifically, if an SVOL-SATA-chunk is corresponded to the PVOL-chunk of which the data update frequency is high, for example, the pool FC-chunk is corresponded as a sub-data swap destination in that SVOL-SATA-chunk.

Abstract: A journal write unit writes journal data into a third storage device. The journal data includes an identifier of a logical volume in a first storage device into which data has been written, information of a location in which the data is stored in the logical volume, update time which is current time acquired from a timing mechanism, and the data. A second write unit refers to update time of the journal data stored in the third storage device, selects journal data for which a difference between current time acquired from the timing mechanism and the update time is longer than a detection time stored in the third storage device, and writes the data into a place indicated by the location information, in a logical volume in the second storage device in the order of update time in the selected journal data.

Abstract: A method of selecting logical volumes that are the targets for data migration to equilibrate the load on a system, based on the accessing data of the physical drives and logical drives under the disk array controllers, without increasing the load of the disk array controller. An external manager communicates with two or more disk array controllers, gathers and manages the access data and the configuration data relating to the physical drives and logical volumes of each disk array controller, and prepares an optimum data migration instruction to equilibrate the access load.

Abstract: A method of selecting logical volumes that are the targets for data migration to equilibrate the load on a system, based on the accessing data of the physical drives and logical drives under the disk array controllers, without increasing the load of the disk array controller. An external manager communicates with two or more disk array controllers, gathers and manages the access data and the configuration data relating to the physical drives and logical volumes of each disk array controller, and prepares an optimum data migration instruction to equilibrate the access load.

Abstract: A storage control system comprises a plurality of controllers, each of the controllers receiving a data-input/output request inputted via an external communication path and sending a data-input/output command to storage means; and an internal communication path through which the controllers carry out the data-input/output command and data input/output. Each of the controllers comprises means for sending its own operational information towards other ones of the controllers via the internal communication path. The storage control system further comprises means for monitoring an operational state of each of the controllers based on the operational information sent from the sending means of the controllers.

Abstract: In a structure where first and second storage devices structure a mirrored pair, at a first time, an updating process to the second storage device is stopped, and management using first and second update-management tables is started. At a second time on or after the first time, management of the first update-management table is started from a non-updated state, and data of the second storage device, stored in the data blocks indicated by the second update-management table as being updated, is copied to a backup medium. At a third time after the second time, data of the first storage device, stored in the data blocks indicated by the second update-management table as being updated, is copied to data blocks of the second storage device corresponding to the data blocks of the first storage device.

Abstract: A storage controller determines a difference between a control table containing fiber channel port configuration of an upper node device and security information, and information fetched from a name server, thereby detecting replacement of a fiber channel port and correcting the control table. This enables data input/output in the same way as before fiber channel port replacement without consciously modifying the security information.

Abstract: A storage controller determines a difference between a control table containing fiber channel port configuration of an upper node device and security information, and information fetched from a name server, thereby detecting replacement of a fiber channel port and correcting the control table. This enables data input/output in the same way as before fiber channel port replacement without consciously modifying the security information.

Abstract: In an external storage, an I/O process is continued without any intervention of a user or a host system at failure of a controller. When a failure occurs in a controller, a host system recognizes the failure of the controller. Before the failure is notified to the user and application to stop the job, the substitutive controller reads the SCSI-ID possessed by an SCSI port of the failed controller from a shared memory, registers the SCSI-ID of the SCSI port to the SCSI port associated with the substitutive controller, and erases by a port address resetting facility of the substitutive controller the SCSI-ID possessed by an SCSI port of the failed controller.

Abstract: A method of selecting logical volumes that are the targets for data migration to equilibrate the load on a system, based on the accessing data of the physical drives and logical drives under the disk array controllers, without increasing the load of the disk array controller. An external manager communicates with two or more disk array controllers, gathers and manages the access data and the configuration data relating to the physical drives and logical volumes of each disk array controller, and prepares an optimum data migration instruction to equilibrate the access load.

Abstract: In an external storage, an I/O process is continued without any intervention of a user or a host system at failure of a controller. When a failure occurs in a controller, a host system 10 recognizes the failure of the controller. Before the failure is notified to the user and application to stop the job, the substitutive controller reads the SCSI-ID possessed by an SCSI port of the failed controller from a shared memory, registers the SCSI-ID of the SCSI port to the SCSI port associated with the substitutive controller, and erases by a port address resetting facility 45 of the substitutive controller the SCSI-ID possessed by an SCSI port of the failed controller. Thanks to the provision, since the SCSI-ID specified at issuance of an I/O request is transferred between the controllers, the user or the host system need not alter the I/O request issuing route. Moreover, while the host system does not recognize the error, the transfer can be conducted.

Abstract: In an external storage, an I/O process is continued without any intervention of a user or a host system at failure of a controller. When a failure occurs in a controller, a host system 10 recognizes the failure of the controller. Before the failure is notified to the user and application to stop the job, the substitutive controller reads the SCSI-ID possessed by an SCSI port of the failed controller from a shared memory, registers the SCSI-ID of the SCSI port to the SCSI port associated with the substitutive controller, and erases by a port address resetting facility 45 of the substitutive controller the SCSI-ID possessed by an SCSI port of the failed controller. Thanks to the provision, since the SCSI-ID specified at issuance of an I/O request is transferred between the controllers, the user or the host system need not alter the I/O request issuing route. Moreover, while the host system does not recognize the error, the transfer can be conducted.

Abstract: In an external storage, an I/O process continues without any intervention of a user of a host system upon failure of a controller. When a failure occurs in a controller, a host system recognizes the failure of the controller. Before the failure is notified to the user and application program to stop the job, the substitute controller reads the SCSI-ID possessed by an SCSI port of the failed controller from a shared memory, registers the SCSI-ID of the SCSI port to the SCSI port associated with the substitute controller, and erases by a port address resetting facility of the substitute controller the SCSI-ID possessed by an SCSI port of the failed controller. Due to such provision, since the SCSI-ID specified at issuance of an I/O request is transferred between the controllers, the user or the host system need not alter the I/O request issuing route.