* Christopher Yeoh <cbky...@gmail.com> wrote: > On Tue, Jan 7, 2014 at 7:50 AM, Jon Bernard <jbern...@tuxion.com> wrote: > > > Hello all, > > > > I would like to propose instance-level snapshots as a feature for > > inclusion in Nova. An initial draft of the more official proposal is > > here [1], blueprint is here [2]. > > > > In a nutshell, this feature will take the existing create-image > > functionality a few steps further by providing the ability to take > > a snapshot of a running instance that includes all of its attached > > volumes. A coordinated snapshot of multiple volumes for backup > > purposes. The snapshot operation should occur while the instance is in > > a paused and quiesced state so that each volume snapshot is both > > consistent within itself and with respect to its sibling snapshots. > > > > I still have some open questions on a few topics: > > > > * API changes, two different approaches come to mind: > > > > 1. Nova already has a command `createImage` for creating an image of an > > existing instance. This command could be extended to take an > > additional parameter `all-volumes` that signals the underlying code > > to capture all attached volumes in addition to the root volume. The > > semantic here is important, `createImage` is used to create > > a template image stored in Glance for later reuse. If the primary > > intent of this new feature is for backup only, then it may not be > > wise to overlap the two operations in this way. On the other hand, > > this approach would introduce the least amount of change to the > > existing API, requiring only modification of an existing command > > instead of the addition of an entirely new one. > > > > 2. If the feature's primary use is for backup purposes, then a new API > > call may be a better approach, and leave `createImage` untouched. > > This new call could be called `createBackup` and take as a parameter > > the name of the instance. Although it introduces a new member to the > > API reference, it would allow this feature to evolve without > > introducing regressions in any existing calls. These two calls could > > share code at some point in the future. > > > > Note there already is a createBackup/create_backup API call implemented in > the admin_actions > extension (in V3 API it is being separated into its own extension > https://review.openstack.org/#/c/62280/) > It doesn't do the all volumes snapshot that you want though. There's a > small window (basically end of icehouse) to make an incompatible change in > the V3 API if that would be the best way to do it.
Thanks for mentioning this. If the consensus is to leave createImage as it is and use a different API call, then createBackup looks like a really nice fit. -- Jon _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
