cinder matrix - clarification of snapshot attachment feature

[Helen Walsh]

https://docs.openstack.org/cinder/rocky/reference/support-matrix.html#operation_attach_snapshot

Wondering if this should be pitched as an optimization rather than missing functionality in the driver and/or backend. In most arrays, snapshots are not attachable entities. The default behavior is that a volume is created from the snapshot and that volume is then attached.

Option 1: remove this feature from the matrix.
Option 2. Call out in 'Notes' that this is an optimization in backup support for drivers that can attach snapshots and is not a gap in functionality for those who don't.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/cinder/+/800015

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/cinder/+/800015
Committed: https://opendev.org/openstack/cinder/commit/89ec25b3d6ce190e0166192ad91dce97e6721343
Submitter: "Zuul (22348)"
Branch: master

commit 89ec25b3d6ce190e0166192ad91dce97e6721343
Author: Helen Walsh <email address hidden>
Date: Thu Jul 8 12:14:13 2021 +0100

    Cinder matrix - Removal of Snapshot Attachment

    This functionality is exposed via rpcapi (as a cinder backup
    enhancement) and not the OpenStack Block Storage API. As such
    it should be removed from the cinder support matrix.

    Closes-Bug: #1934168
    Change-Id: Icaca68a1be8151f4aa0c5a0a6baeb762492bd159

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/cinder 20.0.0.0rc1 release candidate.