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 > 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 > snapshot. > > > On Mon, Sep 30, 2013 at 3:52 PM, Chiradeep Vittal < > chiradeep.vit...@citrix.com> wrote: > >> Is VM Quiescing sufficient to ensure consistency of the snapshot? >> >> >> On 9/30/13 2:43 PM, "SuichII, Christopher" <chris.su...@netapp.com> >> wrote: >> >> >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 snapshot, there are ways around this and >> >'quiescing' the vm without actually quiescing it (through hypervisor >> >APIs). I would like to propose that there be an option to quiesce VMs >> >when taking snapshots both manually and through recurring snapshot >> >policies. One issue I see with this is that this option is not always >> >applicable. If the default storage provider is used, a hypervisor >> >snapshot will be taken and therefore the VM will always be quiesced. Some >> >storage providers may not respect the user's request to quiesce. Because >> >of this, I suggest that the option be shown to the user as 'Quiesce VM >> >(if applicable)'. This indicates to the user that the option will be >> >passed to the management server and respected if possible. >> > >> >I will work on formalizing a full functional spec if needed but wanted to >> >get this up for discussion ASAP. >> > >> >I have created a JIRA ticket: >> >https://issues.apache.org/jira/browse/CLOUDSTACK-4774 >> > >> >Thanks, >> >Chris >> >-- >> >Chris Suich >> >chris.su...@netapp.com<mailto:chris.su...@netapp.com> >> >NetApp Software Engineer >> >Data Center Platforms Cloud Solutions >> >Citrix, Cisco & Red Hat >> > >> >> > > > -- > *Mike Tutkowski* > *Senior CloudStack Developer, SolidFire Inc.* > e: mike.tutkow...@solidfire.com > o: 303.746.7302 > Advancing the way the world uses the > cloud<http://solidfire.com/solution/overview/?video=play> > *™* > -- *Mike Tutkowski* *Senior CloudStack Developer, SolidFire Inc.* e: mike.tutkow...@solidfire.com o: 303.746.7302 Advancing the way the world uses the cloud<http://solidfire.com/solution/overview/?video=play> *™*
