Abstract: A storage controlling apparatus includes a processor, wherein the processor: controls a first counter configured to count, among data stored in a cache memory and relating to an access request, a number of data which are not written in storage volumes of a target of the access request, for each storage volume; determines, in response to reception of a first access request, whether or not a first ratio of a counter value of the first counter to a number of data allocated already to the cache memory into a first storage volume exceeds a first threshold value, the counter value of the first counter corresponding to the first storage volume which is a target of the first access request; and performs a write back process of data from the cache memory into the first storage volume where the first ratio exceeds the first threshold value.

Abstract: A storage controlling apparatus includes a processor, wherein the processor: controls a first counter configured to count, among data stored in a cache memory and relating to an access request, a number of data which are not written in storage volumes of a target of the access request, for each storage volume; determines, in response to reception of a first access request, whether or not a first ratio of a counter value of the first counter to a number of data allocated already to the cache memory into a first storage volume exceeds a first threshold value, the counter value of the first counter corresponding to the first storage volume which is a target of the first access request; and performs a write back process of data from the cache memory into the first storage volume where the first ratio exceeds the first threshold value.

Abstract: A storage control apparatus converts data in a variable-length data format including a field into data in a fixed-length data format and stores the converted data in the fixed-length data format in a storage apparatus. The storage control apparatus includes a data storage memory, a writing unit, and a verification information adding unit. The writing unit writes the data in the variable-length data format to divided regions of the data storage memory. The verification information adding unit adds verification information to the field of the variable-length data format which is written to one or more of the divided regions. Thus, the storage control apparatus is able to check each divided region for a data error.

Abstract: A storage control apparatus includes a detection unit that detects a soft error of a memory for setting information included in a programmable logic circuit, when the soft error is detected, a communication control unit that changes a state of a communication path between the communication device and an upper device to a busy state, and a recovery processing unit that performs recovery processing of the memory for setting information of the programmable logic circuit, thereby efficiently resolving a soft error of the programmable logic circuit.

Abstract: A determining unit selects one storage device each from storage devices of an external storage apparatus and storage devices of a storage apparatus to which the determining unit belongs. At this point, based on a copy request, the determining unit preferentially selects, within each of the external storage apparatus and the storage apparatus, a storage device including a larger number of logical volumes (LVs) which belong to copy unexecuted LV pairs compared to other storage devices therein. Further, the determining unit determines, as a copy execution target, a copy unexecuted LV pair in which a LV provided in one of the selected two storage devices is a copy source and a LV provided in the other storage device is a copy destination. A copy unit copies data stored in the copy source LV, which belongs to the determined LV pair, to the copy destination LV of the LV pair.

Abstract: A storage control apparatus converts data in a variable-length data format including a field into data in a fixed-length data format and stores the converted data in the fixed-length data format in a storage apparatus. The storage control apparatus includes a data storage memory, a writing unit, and a verification information adding unit. The writing unit writes the data in the variable-length data format to divided regions of the data storage memory. The verification information adding unit adds verification information to the field of the variable-length data format which is written to one or more of the divided regions. Thus, the storage control apparatus is able to check each divided region for a data error.

Abstract: By providing a unit storage area usage information calculation unit that calculates, during copy of data by a data copy control unit, usage information of a unit storage area in a storage unit that stores the data transferred from a migration source apparatus, as unit storage area usage information, and a comparison unit that compares data stored in the storage unit related to a unit storage area to be verified, selected based on the unit storage area usage information calculated, with data in the migration source apparatus related to the area to be verified, efficient and reliable data compare can be performed.

Abstract: A storage control apparatus includes a detection unit that detects a soft error of a memory for setting information included in a programmable logic circuit, when the soft error is detected, a communication control unit that changes a state of a communication path between the communication device and an upper device to a busy state, and a recovery processing unit that performs recovery processing of the memory for setting information of the programmable logic circuit, thereby efficiently resolving a soft error of the programmable logic circuit.

Abstract: A determining unit selects one storage device each from storage devices of an external storage apparatus and storage devices of a storage apparatus to which the determining unit belongs. At this point, based on a copy request, the determining unit preferentially selects, within each of the external storage apparatus and the storage apparatus, a storage device including a larger number of logical volumes (LVs) which belong to copy unexecuted LV pairs compared to other storage devices therein. Further, the determining unit determines, as a copy execution target, a copy unexecuted LV pair in which a LV provided in one of the selected two storage devices is a copy source and a LV provided in the other storage device is a copy destination. A copy unit copies data stored in the copy source LV, which belongs to the determined LV pair, to the copy destination LV of the LV pair.

Abstract: By providing a unit storage area usage information calculation unit that calculates, during copy of data by a data copy control unit, usage information of a unit storage area in a storage unit that stores the data transferred from a migration source apparatus, as unit storage area usage information, and a comparison unit that compares data stored in the storage unit related to a unit storage area to be verified, selected based on the unit storage area usage information calculated, with data in the migration source apparatus related to the area to be verified, efficient and reliable data compare can be performed.

Abstract: A transfer control method includes a selecting step which selects one of a first route for making an asynchronous transfer to a request destination via a control block and a second route for making a synchronous transfer to the request destination by not passing the control block, with respect to a request from a request source.