Nova using ephemeral storage with cinder
As a cloud provider I would like to manage all the storage related activities through one entity: cinder. The ambition is that cinder could decide what back-end to use based on SLAs (e.g low-performing or high-performing but also persistent or ephemeral). Those SLAs could come from the tenant or from the infrastructure and thus, cinder shall serve the needs for nova's ephemeral storage, glance image storage and cinder block storage.
As there is development ongoing in glance to use cinder as image backend, we have to address the usage in nova to use ephemeral storage with cinder as backend. The workaround using bootable volumes is not seen as a future proof solution, because it requires explicit calls to Cinder API and therefor additional burden on the user as just calling nova is not sufficient.
Proposal
- VM boot requested by the tenant
- Nova tries to find an "ephemeral" volume for the VM
- Today nova will use the local disk. This blueprint suggests to change nova to be able to use a cinder volume as ephemeral storage instead of local disk.
Related Topic:
https:/
Blueprint information
- Status:
- Not started
- Approver:
- None
- Priority:
- Undefined
- Drafter:
- None
- Direction:
- Needs approval
- Assignee:
- John Griffith
- Definition:
- New
- Series goal:
- None
- Implementation:
-
Unknown
- Milestone target:
- None
- Started by
- Completed by
Related branches
Related bugs
Sprints
Whiteboard
Gerrit topic: https:/
Addressed by: https:/
Implements: blueprint nova-ephemeral-
Gerrit topic: https:/
This came up again at the Pike PTG, and John Griffith was interested in working on this.
http://
-- mriedem 20170306
Alternative (rejected): https:/
We are now past the spec freeze for the Pike release so I'm untargeting this from Pike. We do have a session planned for the Forum at the Boston summit for this idea:
So we should gather feedback and requirements from operators so we can start building a spec and plan for doing this in Queens. -- mriedem 20170418
