Dynamically Growing and Shrinking Snapshot Repositories Without Impacting Performance or Latency

摘要

A system, method, and computer program product for the provision of a snapshot repository that grows and shrinks over time. The snapshot repository stores snapshot images. When the used capacity of the repository reaches an upper bound of the repository, the image may be wrapped to the start of the repository if the image stored there previously has been deleted. Otherwise another stripe volume is added from a pool of available volumes and the image continues storage there. As older images are deleted according to a retention policy, stripe volumes that become empty may be dis-associated from their associated LBA range and released to the pool or re-mapped to a lower LBA range of the repository. When the empty stripe volume is at the end of the repository, the ending LBA may be adjusted to the end of the last allocated stripe volume as the volume is released.