Volume multiattach enhancements
This blueprint intends to enhance volume multiattach support in two ways related to issues brought up at the Rocky PTG:
https:/
1. Add the ability to boot multiple servers in a single request from a multiattach-capable volume.
Related bug: https:/
Users currently cannot create multiple servers in a single request with a multiattach volume because the compute API specifically blocks more than one server trying to attach to the same volume (and is not multiattach aware in that respect).
2. Add the ability to pass through the attach_mode when attaching volumes.
Related bug: https:/
Currently all secondary attachments to a multiattach volume are in read/write mode. Users would like the ability to be able to specify that attachments to a multiattach volume are read-only. Nova will simply pass this through to Cinder when creating (or updating) the attachment (the attach mode is specified in the host connector parameter to POST /attachments and PUT /attachments/{id}).
While specifying a read-only attach mode really only makes sense when using multiattach volumes, the compute API will not distinguish between multiattach-capable volumes and non-multiattach
https:/
--
Both changes will be made in a single microversion.
Blueprint information
- Status:
- Started
- Approver:
- Dan Smith
- Priority:
- Medium
- Drafter:
- Matt Riedemann
- Direction:
- Needs approval
- Assignee:
- Matt Riedemann
- Definition:
- Pending Approval
- Series goal:
- None
- Implementation:
-
Started
- Milestone target:
- None
- Started by
- Matt Riedemann
- Completed by
Related branches
Related bugs
Sprints
Whiteboard
Gerrit topic: https:/
Addressed by: https:/
Spec for volume multiattach enhancements
Addressed by: https:/
Add block_device_
Addressed by: https:/
Add BlockDeviceMapp
Addressed by: https:/
Add plumbing to pass attach_mode when creating/updating attachments
Addressed by: https:/
Use BDM.attach_mode when creating/updating volume attachments
Approved for Rocky. -- mriedem 20180607
I'm deferring this to Stein. I won't be able to have the API changes written and properly tested by the Rocky feature freeze in 3 days so I'll re-propose the spec for Stein and work on it then. -- mriedem 20180723
I'm not working on this in Stein. There is still merit in the blueprint, which was approved in Rocky, but it's low priority. Could be picked up again later if someone has a pressing need for it. -- mriedem 20181025
