Abstract: A storage control apparatus of the present invention reduces the frequency of disk drive failures. An error management part manages the number of times errors occur in respective disk drives. A disk drive in which the number of errors meets or exceeds a threshold value is selected as a disk drive to be restarted. A restart control part commences difference management prior to restarting the disk drive targeted for restart. A difference management part manages parity group-related update locations using a difference bitmap. After commencing difference management, the restart control part restarts the disk drive in which the error was detected. This makes it possible to resolve an error caused by a firmware hangup or the like.

Abstract: The configuration of a cache memory can be changed while minimizing the influence over input-output performance with a host system on the active storage system. A data transfer control unit transfers data via a cache memory by a write-after method; and as triggered by an event where an amount of input to and output from an object area in the cache memory falls below a certain value, the data transfer control unit switches from the write-after method to a write-through method and then transfers data via the cache memory. Subsequently, as triggered by an event where there is no longer any input to and output from the object area in the cache memory, a processor changes the configuration of the cache memory relating to the object area.

Abstract: A storage control apparatus of the present invention reduces the frequency of disk drive failures. An error management part manages the number of times errors occur in respective disk drives. A disk drive in which the number of errors meets or exceeds a threshold value is selected as a disk drive to be restarted. A restart control part commences difference management prior to restarting the disk drive targeted for restart. A difference management part manages parity group-related update locations using a difference bitmap. After commencing difference management, the restart control part restarts the disk drive in which the error was detected. This makes it possible to resolve an error caused by a firmware hangup or the like.

Abstract: A storage control apparatus of the present invention reduces the frequency of disk drive failures. An error management part manages the number of times errors occur in respective disk drives. A disk drive in which the number of errors meets or exceeds a threshold value is selected as a disk drive to be restarted. A restart control part commences difference management prior to restarting the disk drive targeted for restart. A difference management part manages parity group-related update locations using a difference bitmap. After commencing difference management, the restart control part restarts the disk drive in which the error was detected. This makes it possible to resolve an error caused by a firmware hangup or the like.

Abstract: A storage control apparatus of the present invention reduces the frequency of disk drive failures. An error management part manages the number of times errors occur in respective disk drives. A disk drive in which the number of errors meets or exceeds a threshold value is selected as a disk drive to be restarted. A restart control part commences difference management prior to restarting the disk drive targeted for restart. A difference management part manages parity group-related update locations using a difference bitmap. After commencing difference management, the restart control part restarts the disk drive in which the error was detected. This makes it possible to resolve an error caused by a firmware hangup or the like.

Abstract: A storage control apparatus of the present invention reduces the frequency of disk drive failures. An error management part manages the number of times errors occur in respective disk drives. A disk drive in which the number of errors meets or exceeds a threshold value is selected as a disk drive to be restarted. A restart control part commences difference management prior to restarting the disk drive targeted for restart. A difference management part manages parity group-related update locations using a difference bitmap. After commencing difference management, the restart control part restarts the disk drive in which the error was detected. This makes it possible to resolve an error caused by a firmware hangup or the like.

Abstract: A storage control apparatus of the present invention reduces the frequency of disk drive failures. An error management part manages the number of times errors occur in respective disk drives. A disk drive in which the number of errors meets or exceeds a threshold value is selected as a disk drive to be restarted. A restart control part commences difference management prior to restarting the disk drive targeted for restart. A difference management part manages parity group-related update locations using a difference bitmap. After commencing difference management, the restart control part restarts the disk drive in which the error was detected. This makes it possible to resolve an error caused by a firmware hangup or the like.

Abstract: The storage control device and storage device error control method of the present invention prevent incorrect data from being read out to the host in advance, and thus improve the reliability. For example, the controller 5 that controls the disk array subsystem disperses and stores data on respective disks 1 through 3, calculates parity data, and stores this parity data on a disk 4. In cases where the updating of a certain block (D12) fails, so that data is not written into this block, this is an uncorrectable error. The data of this block (D12) is recovered on the basis of data and parity data stored on the other disks. The controller 5 also recovers data for another block (D13) following the block (D12) on the basis of other associated data and parity data. As a result, even if by some chance the block (D13) which has not suffered an uncorrectable error stores old data, the correct data can be recreated and provided to the host 7.

Abstract: The storage control device and storage device error control method of the present invention prevent incorrect data from being read out to the host in advance, and thus improve the reliability. For example, the controller 5 that controls the disk array subsystem disperses and stores data on respective disks 1 through 3, calculates parity data, and stores this parity data on a disk 4. In cases where the updating of a certain block (D12) fails, so that data is not written into this block, this is an uncorrectable error. The data of this block (D12) is recovered on the basis of data and parity data stored on the other disks. The controller 5 also recovers data for another block (D13) following the block (D12) on the basis of other associated data and parity data. As a result, even if by some chance the block (D13) which has not suffered an uncorrectable error stores old data, the correct data can be recreated and provided to the host 7.

Abstract: A disk array device that prevents the processing of the host device from being interrupted or delayed by drive idle seek, idle seek being executed by all the drives at approximately fixed intervals. The disk array device predicts the approach of the scheduled times to start idle seek of each of the disk drives 23, 23, . . . and exercises control so that, within the same parity group, idle seek is not executed by two or more drives 23, 23, . . . at the same time. Within the same parity group, one of the drives whose idle seek scheduled start time is approaching is considered in advance to be executing idle seek and hence data access is denied beforehand. When a data read request with respect to the drive 23 that is considered to be executing idle seek is received, the required data is recovered by reading data from all the other drives 23, 23, . . . belonging to the same parity group.

Abstract: A disk array device that prevents the processing of the host device from being interrupted or delayed by drive idle seek, idle seek being executed by all the drives at approximately fixed intervals. The disk array device predicts the approach of the scheduled times to start idle seek of each of the disk drives 23, 23, . . . and exercises control so that, within the same parity group, idle seek is not executed by two or more drives 23, 23, . . . at the same time. Within the same parity group, one of the drives whose idle seek scheduled start time is approaching is considered in advance to be executing idle seek and hence data access is denied beforehand. When a data read request with respect to the drive 23 that is considered to be executing idle seek is received, the required data is recovered by reading data from all the other drives 23, 23, . . . belonging to the same parity group.