Patent ID: 9128746
Filing Date: 2015-09-08
Classification: G06F

Abstract:
1. In a computer system having virtual machines executed therein and a hypervisor supporting execution of the virtual machines, a method of issuing commands to release storage allocated to a logical block device by a storage device, comprising: upon deleting a file or receiving a command to delete a file, moving the file into a delete directory; cycling through one or more files in the delete directory and, for each file, issuing an unmap command to the storage device to release one or more blocks of the logical block device that are allocated thereto according to a file selection criterion; maintaining a block map that tracks which of blocks of the logical block device are free for allocation and are pending unmap; marking the blocks included in the unmap command as pending unmap in the block map; and upon receiving acknowledgement from the storage device that the blocks have been unmapped, marking the blocks as free in the block map.