Patent ID: 7685400

Claim:
A method for processing logical data blocks in a storage system that virtualizes logical volumes by using attached physical storage, comprising: dividing a physical storage space into a plurality of physical pages; allocating a plurality of physical blocks to each physical page, each physical block having a position number, and each physical page having the same number of physical blocks; logically concatenating a plurality of physical pages to create storage space for each of a plurality of logical volumes, each logical volume having a logical volume number n, whereby: each physical page is mapped to a logical page of one of the plurality of logical volumes, each logical page having a logical page number m; the logical pages are ordered from the logical volume's perspective; and each logical page contains the same number of logical blocks as a physical page contains physical blocks; assigning to each logical block an associated sequence number N; calculating a physical block position within a physical page for each logical block of a logical page m of a logical volume n as (N+T) modulo x, where T is a number selected from the group comprising m, n and m+n, and each logical page is x logical blocks in size, whereby no correlation exists between the physical block positions of the logical blocks within physical pages and the associated sequence numbers of the logical blocks; and storing each logical block and the associated sequence number N in the calculated physical block position within the physical page associated with the logical page of the logical volume.