cinder: Attach a single volume to multiple instances

Registered by Walt Boring on 2014-04-07

This is a blueprint place holder for Nova's work to support Cinder's multi-attach capability.

More details:

Blueprint information

John Garbutt
Walt Boring
Ildiko Vancsa
Series goal:
Accepted for queens
Milestone target:
Started by
John Garbutt on 2014-12-17

Related branches



Gerrit topic:,topic:bp/multi-attach-volume,n,z

Addressed by:
    WIP Add volume multi attach support

Gerrit topic:,topic:bp/for,n,z

Addressed by:
    Blueprint for Cinder Multi attach volumes

Old patches

Addressed by:
    Add volume multi-attach support

Addressed by:
    First commit of the splitted work in Multi Attach

Remaining patch appear to be this:

Addressed by:
    Allow multiple volume attachments

Addressed by:
    REST API changes to support multiple volume attach

Sorry, we have now hit the non-priority feature freeze for kilo. Please resubmit your spec for the L release. --johnthetubaguy 5th Feb 2015

Reapprove for liberty --johnthetubaguy 5th June 2015

Addressed by:
    Add REST API impact to the multi-attach spec

Addressed by:
    obj: Allow multiple volume attachments

Addressed by:
    comp: Allow multiple volume attachments

Addressed by:
    virt: Allow multiple volume attachments

Gerrit topic:,topic:bp/volume-multi-attach,n,z

Please note this blueprint will delayed until the M release if it is not in the NeedsCodeReview state (i.e. all the code up for review) before July 16th, and merged by July 30th. We expect to re-open master for the M release in September. For more information, please see: and
--johnthetubaguy 15th July 2015

While the API changes are still marked as WIP, it does look close-ish. So moving this to NeedsCodeReview, so it can continue to get reviewed. --johnthetubaguy 16th July 2015

Sorry, we have now hit the non-priority feature freeze for Liberty. You will need to resubmit this blueprint for Mitaka or apply for an exception. For more details on why this is happening, and the rest of the process details, please see:
--johnthetubaugy 3rd July 2015

Addressed by:
    comp: Allow volume multiattach

Addressed by:
    WIP: Modify API response to reflect on multiattach changes

At the midcycle we agreed to defer the bulk of this work to Newton. --johnthetubaguy 2016.02.08

Addressed by:
    Add multiattach support to Nova

This still has outstanding changes and we're now at non-priority blueprint
feature freeze for Newton. -- mriedem 20160630

Addressed by:
    Add multiattach support to Nova

Approved for Queens. -- mriedem 20171019

Gerrit topic:,topic:bp/cinder-new-attach-apis,n,z

Addressed by:
    Add new style volume attachment support to

Addressed by:
    Implement new attach Cinder flow

Addressed by:
    Avoid stashed connector lookup for new style detach


Work Items

Dependency tree

* Blueprints in grey have been implemented.