1. A method of issuing a command to deallocate free storage blocks previously allocated to a logical block device, comprising: determining that the logical block device supports the command; identifying one or more sets of contiguous storage blocks to be deallocated; and issuing the command to the logical block device based on alignment and granularity values according to which the logical block device performs space reclamation operations, the command identifying at least one set of contiguous storage blocks as storage blocks to be deallocated.