US Patent 9658959 Cache resource manager

A resource manager directs cache operating states of virtual machines based on cache resource latency and by distinguishing between latencies in flash memory and latencies in network communications and by distinguishing between executing read commands and executing different types of write commands. As a result, the resource manager can downgrade the cache operating state of the virtual machines differently based on the type of latency being experienced and the type of command being performed. The resource manager can upgrade and/or reset the cache operating state of the virtual machines, when appropriate, and can give priority to some virtual machines over other virtual machines when operating in a downgraded cache operating state.