Re: [PROPOSAL] Provide Option to Quiesce VMs While Taking Snapshots

2013-09-30 Thread Mike Tutkowski
Yeah, I've been through a project that dealt with application-level quiescing - as you say, that's a much larger undertaking. Thanks for the clarification. On Mon, Sep 30, 2013 at 6:38 PM, SuichII, Christopher < chris.su...@netapp.com> wrote: > I should clarify (because it may not have been cle

Re: [PROPOSAL] Provide Option to Quiesce VMs While Taking Snapshots

2013-09-30 Thread SuichII, Christopher
I should clarify (because it may not have been clear) that I'm talking about vm disk snapshots which go through the storage subsystem API, NOT entire VM snapshots. The important distinction is that calls to the storage subsystem would not snapshot VM memory - just VM volumes. In general, you're

Re: [PROPOSAL] Provide Option to Quiesce VMs While Taking Snapshots

2013-09-30 Thread Mike Tutkowski
VM quiescing should be sufficient for hypervisor snapshots, though, because you are presumably snapping the disks and the memory. On Mon, Sep 30, 2013 at 4:02 PM, Mike Tutkowski < mike.tutkow...@solidfire.com> wrote: > I would say 'no'. Let's say you have a DB app running in your host OS and > i

Re: [PROPOSAL] Provide Option to Quiesce VMs While Taking Snapshots

2013-09-30 Thread Mike Tutkowski
I would say 'no'. Let's say you have a DB app running in your host OS and it's in the middle of writing a transaction to a data disk...quiescing the VM - without quiescing the DB app (like SQL Server via VSS) - does not give you a properly quiesced snapshot on the data disk - just a point-in-time s

Re: [PROPOSAL] Provide Option to Quiesce VMs While Taking Snapshots

2013-09-30 Thread Chiradeep Vittal
Is VM Quiescing sufficient to ensure consistency of the snapshot? On 9/30/13 2:43 PM, "SuichII, Christopher" wrote: >CloudStack currently snapshots vm disks by taking hypervisor snapshots. >However, when implementing the storage subsystem API interface >takeSnapshot(), the VM associated with th

[PROPOSAL] Provide Option to Quiesce VMs While Taking Snapshots

2013-09-30 Thread SuichII, Christopher
CloudStack currently snapshots vm disks by taking hypervisor snapshots. However, when implementing the storage subsystem API interface takeSnapshot(), the VM associated with the requested volume is not quiesced since a hypervisor snapshot is not necessarily taken. When creating a storage level s