BIG +1 My team should submit some patch to ACS for better KVM snapshots, including whole VM snapshot etc...but it's too early to give details... best
On 16 February 2015 at 13:01, Andrei Mikhailovsky <and...@arhont.com> wrote: > Hello guys, > > I was hoping to have some feedback from the community on the subject of > having an ability to keep snapshots on the primary storage where it is > supported by the storage backend. > > The idea behind this functionality is to improve how snapshots are > currently handled on KVM hypervisors with Ceph primary storage. At the > moment, the snapshots are taken on the primary storage and being copied to > the secondary storage. This method is very slow and inefficient even on > small infrastructure. Even on medium deployments using snapshots in KVM > becomes nearly impossible. If you have tens or hundreds concurrent > snapshots taking place you will have a bunch of timeouts and errors, your > network becomes clogged, etc. In addition, using these snapshots for > creating new volumes or reverting back vms also slow and inefficient. As > above, when you have tens or hundreds concurrent operations it will not > succeed and you will have a majority of tasks with errors or timeouts. > > At the moment, taking a single snapshot of relatively small volumes (200GB > or 500GB for instance) takes tens if not hundreds of minutes. Taking a > snapshot of the same volume on ceph primary storage takes a few seconds at > most! Similarly, converting a snapshot to a volume takes tens if not > hundreds of minutes when secondary storage is involved; compared with > seconds if done directly on the primary storage. > > I suggest that the CloudStack should have the ability to keep volume > snapshots on the primary storage where this is supported by the storage. > Perhaps having a per primary storage setting that enables this > functionality. This will be beneficial for Ceph primary storage on KVM > hypervisors and perhaps on XenServer when Ceph will be supported in a near > future. > > This will greatly speed up the process of using snapshots on KVM and users > will actually start using snapshotting rather than giving up with > frustration. > > I have opened the ticket CLOUDSTACK-8256, so please cast your vote if you > are in agreement. > > Thanks for your input > > Andrei > > > > > -- Andrija Panić
