Patent ID: 7340640

Claim:
A system comprising: a volume server; a first and a second host computer system; and a plurality of physical block devices; wherein the volume server is configured to: aggregate storage in the plurality of physical block devices into a plurality of logical volumes, wherein a particular logical volume includes storage from at least two physical block devices; make a first subset of the logical volumes available to said first host computer system for input/output; and make a second subset of the logical volumes available to said second host computer system for input/output; wherein the volume server is further configured to distribute a volume description of a given one of said logical volumes to a volume client on a given one of said first and second host computer systems to make said given volume available to said given host computer system for input/output, wherein said volume description indicates storage mapping relationships between said given logical volume and ones of said physical block devices included in said given logical volume; wherein, after said given logical volume has been made available to said given host computer system by said volume server, said given host computer system is operable to read and write data to said given logical volume without interacting with said volume server; wherein said first subset and said second subset are at least partially nonoverlapping; wherein said given logical volume is configured as a mirrored logical volume including a plurality of copies of a given data block; and wherein the system further comprises recovery functionality configured to place two of said plurality of copies of said given data block in a mutually consistent state if said two copies of said given data block are detected to be possibly inconsistent.