Direct host-to-host transfer for local cache in virtualized systems wherein hosting history stores previous hosts that serve as currently-designated host for said data object prior to migration of said data object, and said hosting history is checked during said migration

摘要

A request is received to access at least one data unit of a larger data object by an entity within a local host, which is then queried to determine if the requested data unit is present. If the requested data unit is present in the local cache, it is fetched from the local cache. If the requested data unit is not present in the local cache, however, a respective cache within at least one target host, which is different from the local host, is queried to determine if the requested data unit is present remotely and, if so, the data unit is fetched from there instead. If the requested data unit is not present in the local cache or the cache of the target host, the data unit is fetched from a common data storage pool.