STORAGE SYSTEM, AND DATA BACKUP METHOD AND SYSTEM RESTARTING METHOD OF STORAGE SYSTEM

摘要

In a storage system for performing data backup using a battery during blackout, when the blackout continues for a long time, problems such as the loss of volatile memory data due to the consumption of battery capacity and the difference in recovery time between controller units after power recovery occur during restarting of the system. The present invention solves the problems by selecting (a1) battery backup or (a2) saving of data in a nonvolatile device based on the battery capacity or setting of modes, and selecting (b1) inhibiting restart of the system or (b2) storing of data in the volatile memory to a nonvolatile memory means and performing access via write-through based on the remaining capacity of the battery when restarting the system after power recovery. Further, the system enables to increase and decrease the volatile memory capacity of the write area and mutually confirms synchronization of controller units and contents of volatile memories. Thereby, the system enables to prevent data loss and inconsistency of data.