Patent ID: 8775733

Claim:
A storage system comprising: a data storage unit including a plurality of storage devices; a storage controller including a processor, a memory, and a controller for controlling data transfer between the memory and corresponding storage devices in the data storage unit; and an internal network coupled between the storage controller and the storage devices; wherein based on loads of the processor of the storage controller and the internal network, the storage controller controls to limit a number of redundant storage devices over which to distribute a write data; wherein the storage system calculates network bandwidth of the internal network and processor bandwidth of the processor in a rebuild process, based on performance and number of each component of the storage system except the storage devices, and calculates a maximum distribution number of redundant storage devices over which to distribute the write data based on the network bandwidth and the processor bandwidth; and wherein the storage system compares the newly calculated maximum distribution number with a previous maximum distribution number and, if (i) the two maximum distribution numbers are different or (ii) if a current number of storage devices is different from a previous number of storage devices in the storage system and the current number is higher than the newly calculate maximum distribution number, then changes a list of pairable storage devices so that a number of pairable storage devices on the list is equal to the newly calculated maximum distribution number.