Snapshot properties

Properties include basic properties of a snapshot and specific requirements that must be met.

The basic properties of a snapshot are:
  • Snapshot states:
    • ready: A snapshot is created but not triggered.
    • active: Maintaining the point-in-time image.
    • deleting: Process of deleting.
    • dependent_deleting: The snapshot is instructed to be deleted but is being used to populate a clone, thin-clone, or is being used in a restore operation. Once the snapshot is no longer needed for these tasks, it automatically deletes.
  • Snapshots are immutable, meaning that their content is protected from manipulation by the host.
  • Snapshots consume space in the parent volume’s storage pool. By default, they are in the same pool as the parent volume, but they can be added to child pool of the parent volume’s pool. Or, if the parent volume is in a child pool itself, then they can be added to a child pool that has the same parent pool as the parent volumes pool.
  • Expiration time value is assigned at the time a snapshot is created based on the source volume being part of a volume group with a snapshot policy.
    Note: On detection of an anomaly that leads to a Threat detection event, the latest volume group snapshot expiration time is extended to 7 days if it would otherwise expire beforehand. Snapshots created after the anomaly link to the anomaly fix procedure.
To add snapshots to a volume group or set of volumes, the following requirements must be met:
  • Snapshots cannot be added to the volumes that are target volumes of legacy FlashCopy® mappings.
  • On the SAN Volume Controller platform, volume group snapshots can be added to groups of volumes that are mirrored. On other platforms, volume mirroring is not permitted except in the migration use-case.
  • Volumes of zero size cannot have snapshots.