Patent ID: 8656119

Claim:
A storage system, comprising: a plurality of physical storage devices for providing storage resources to a plurality of logical devices; a plurality of disk interfaces coupled to the physical storage devices; a plurality of host interfaces; one or more processing units, each of which includes one or more processors and a local memory coupled to the processors; and a shared memory coupled to the processors, the shared memory including control information necessary for processing I/O requests to each of the logical devices from a host computer through one or more of the host interfaces, wherein for each of the logical devices, one of the processing units is allocated to be responsible for processing I/O requests for the corresponding logical device that it is responsible for, wherein, the one or more processors of each of the processing units are configured to: cache at least part of the control information in the local memory of the processing unit necessary for processing I/O requests to the corresponding logical device which the processing unit is responsible for, from the shared memory to the local memory of the processing unit, and when updating the cached control information in the processor unit, reflect the update to control information in the shared memory corresponding to the updated control information in the processor, and send a notification of the update of the control information to processors of at least one other processing unit if the updated control information is common control information for said at least one of the processing unit.