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 >
