Disk array device and its control method

Abstract

To shorten the time from power restoration to the resumption of business operation. During a power failure, a memory controller saves configuration information and directory information of a shared memory to a nonvolatile memory, and saves data of a cache memory to the nonvolatile memory. During power restoration from a power failure, the memory controller returns information of the nonvolatile memory to the shared memory so that it can be updated before the lapse of the initialization time, the micro processor executes online processing based on information of the shared memory, and the memory controller 70 controls the storage area of the cache memory so that it will become gradually writable according to the battery capacity of the battery if the battery capacity of the battery is still gradually increasing even after the lapse of the initialization time.

1 . A storage system comprising:
 a plurality of storage devices for storing data;   a controller for performing I/O processing to the plurality of storage devices;   a cache memory for temporarily storing data corresponding to the I/O processing of the controller;   a shared memory for storing management information of the cache memory;   a nonvolatile memory for saving data stored in the cache memory and data stored in the shared memory; and   a battery for feeding electric power to the cache memory and the shared memory,   wherein the controller is configured to start performing the I/O processing when capacity of the battery is charged sufficient to saving data of the shared memory to the nonvolatile memory.   
     
     
         2 . The storage system according to  claim 1 ,
 wherein the cache memory is enabled when the capacity of the battery is charged sufficient to the data of the shared memory and data of the cache memory to the nonvolatile memory.   
     
     
         3 . The storage system according to  claim 2 ,
 wherein if the controller receives a write command before the cache memory is enabled, the controller is configured to write data of the write command to the storage devices without writing the data of the write command to the cache memory.   
     
     
         4 . The storage system according to  claim 1 ,
 wherein the cache memory is enabled according to the on-demand capacity of the battery.   
     
     
         5 . The storage system according to  claim 1 ,
 wherein data of the shared memory is preferentially saved to the nonvolatile memory.   
     
     
         6 . The storage system according to  claim 1 ,
 wherein the shared memory and the cache memory are included in a volatile memory.   
     
     
         7 . The storage system according to  claim 1 ,
 wherein the shared memory and the cache memory are included in a volatile memory.   
     
     
         8 . The storage system according to  claim 1 ,
 wherein the controller is configured to;
 storage the data of the shared memory and data of the cache memory to the nonvolatile memory when a power failure occurs; 
 restore the data stored in the nonvolatile memory to the shared memory and/or the cache memory if a power restoration occurs; 
 start performing the I/O processing; and 
   the cache memory is enabled according to the capacity of the battery.