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Difference between revisions of "Snapshot as full objects"

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* Allowing Volumes to be dependent on the snapshot they were cloned from.
 
* Allowing Volumes to be dependent on the snapshot they were cloned from.
 
* Allowing time consuming operations involved in creating/replicating a snapshot to be tracked in the Snapshot status.
 
* Allowing time consuming operations involved in creating/replicating a snapshot to be tracked in the Snapshot status.
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The states of a snapshot as created using ZFS are very simple:
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* Full Snapshot: as created.
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* Pending Delete: the user has deleted this snapshot but it is still referenced by a later incremental snapshot.
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* Inbound: This snapshot has been created on this backend as a target of a snapshot replication. The snapshot is not yet usable, however.
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Other Volume Drivers may need to identify additional states. For example, an implementation might have a "Creating" state where a
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snapshot is in the process of being created, but where it cannot yet be used to clone a new volume.
  
 
This is part of the [[CERSS]] initiative.
 
This is part of the [[CERSS]] initiative.

Revision as of 18:44, 18 November 2013

Currently there isn't a lot you can do with Snapshots in Cinder. You can create them. You can clone a volume from them. You can delete them.

The proposal is to make Snapshots first class Cinder objects by:

  • defining a "snapshot replicate" method which can replicate a snapshot to another storage backend with the same type of Volume Driver.
  • Optionally allowing the Volume Driver to direct storage-backend to storage-backend transfer of snapshots.
  • Allowing a snapshot to be dependent on a prior snapshot of the same volume stored on the same backend.
  • Allowing Volumes to be dependent on the snapshot they were cloned from.
  • Allowing time consuming operations involved in creating/replicating a snapshot to be tracked in the Snapshot status.

The states of a snapshot as created using ZFS are very simple:

  • Full Snapshot: as created.
  • Pending Delete: the user has deleted this snapshot but it is still referenced by a later incremental snapshot.
  • Inbound: This snapshot has been created on this backend as a target of a snapshot replication. The snapshot is not yet usable, however.

Other Volume Drivers may need to identify additional states. For example, an implementation might have a "Creating" state where a snapshot is in the process of being created, but where it cannot yet be used to clone a new volume.

This is part of the CERSS initiative.