摘要:
A control apparatus includes a capacitor to store electric power supplied from the power supply unit and to supply the stored electric power to the control apparatus when the power supply from the power supply unit is stopped, a first nonvolatile memory, a second nonvolatile memory, a first controller, and a second controller. The first controller writes the data, stored in the cache memory, into the first nonvolatile memory when the external power supply is stopped verifies whether the data stored in the first nonvolatile memory is normal, and sends information of area where the data in the first nonvolatile memory is not normal when the verification indicates that the writing is not normal. And the second controller writes the information sent from the first controller into the second nonvolatile memory.
摘要:
A backup method makes a backup of cache data to a nonvolatile memory by using a controller, the cache data being stored in the volatile memory. The backup method includes writing the cache data stored in the volatility memory in a selected area of the nonvolatile memory, generating party data by operating the parity operations between each of the predetermined parts of the cache data in the volatile memory, verifying whether an error found in the part of the cache data in the nonvolatile memory can be recovered by using the parity data, and rewriting the part of the cache data when the error found in the part of the cache data in the nonvolatile memory cannot be recovered by using the parity data in an area of the nonvolatile memory different from the selected area.
摘要:
A Direct Memory Access (DMA) controller issues a read request to read data stored in a cache memory and sends a cache controller the read request via a bridge chip. When a response time monitored by a response time monitor exceeds a predetermined time, a status information notification unit obtains a measured value of a throughput from a throughput measuring unit and sends the cache controller a notification of both delay in the response time and the status information of a bus. A suppression instruction counting unit counts the number of suppression instructions, issued from the cache controller, to suppress a read request and sends a suppression control unit a notification of the number of suppression instructions. Then, the suppression control unit indicates a waiting time corresponding to the number of suppression instructions to the DMA controller to perform control to suppress issuance of a read request.
摘要:
A storage system has a first power supply unit, a second power supply unit for supplying electronic power to the storage system when the first power supply unit is not supplying electronic power to the storage system, a storage for storing data, a first memory for storing data, a control unit for reading out data stored in the storage and writing the data into the first memory, and reading out data stored in the first memory and writing the data into the storage, a second memory for storing cache data, a table indicating whether each of the data stored in the first memory is to be evacuated to the second memory or not, respectively, and an evacuating unit for evacuating the data stored in the first memory to the second memory in reference to the table when the second power supply unit is supplying electronic power to the storage system.