Methods and apparatus for accessing content in a virtual pool on a content addressable storage system

One embodiment is directed to a method of segregating one or more content addressable storage systems into a plurality of virtual pools. The virtual pools can be allocated to different content sources and/or can be assigned to different storage system capabilities. Another embodiment is directed to transmitting with an input/output request for a content unit information specifying at least one storage capability to be applied to the content unit, and/or receiving such an I/O and implementing the specified storage system capabilities. Another embodiment is directed to extracting from an I/O request from a source information relating to an impact of the I/O on at least one characteristic of the content units stored on a CAS system from the source. Another embodiment is directed to storing information for content identifying the source and/or reading information associated with a stored content unit and determining based at least in part thereon, at least one characteristic of the content units stored from a source.