Patent ID: 9652163
Date: 2017-05-16
CPC Classifications: G06F

Claim:
1. A method for releasing storage space in a space-efficient volume, the method comprising: maintaining, for a space-efficient volume, a bitmap comprising a bit for each track in the space-efficient volume; storing the bitmap in a volume table of contents (VTOC) associated with the space-efficient volume; enabling a storage controller to identify and utilize the bitmap within the VTOC by performing at least one of the following: (1) registering the bitmap with the storage controller at the time the space-efficient volume is initialized; and (2) storing a unique identifier with the bitmap to enable the storage controller to locate the bitmap on the space-efficient volume; indicating, by a host system, whether a track is one of used and unused by marking the corresponding bit in the bitmap; reading, by the storage controller, the bitmap; and freeing, by the storage controller, tracks from the space-efficient volume that the bitmap indicates are unused.