Don't think of CS snapshots the same way you do as VMWare snapshots. CloudStack snapshots are WHOLE COPY BACKUPS of the instance. Also, in regards to snapshot chains, I know VMWare has a default setting per VM of 32 snapshots. If you exceed this, it will stop you from creating a new one. You can, however, modify that setting so that you can create more. I am not sure if XenServer has the same type of setting.
On Sun, Jul 14, 2013 at 8:43 PM, Yong Chen <[email protected]> wrote: > Hi, > > I'm using CS 4.0.1 and XS 6.0.2. There is a problem with taking snapshots > of instances. > > Some of VMs have scheduled snapshots (e.g. weekly, monthly) so eventually > there will be quite some number of snapshots on secondary storage. This is > fine as I read CloudStack should copy snapshots to secondary storage and > then coalesce snapshots on primary storage so can keep the chain not too > long (like 3-4 child normally). > > However I found after snapshot been taken for a while it starts failing > due to error logged on CS Management log 'SR_BACKEND_FAILURE_109The > snapshot chain is too long'. I verified it by checking with vhd-util and it > does show the affected VHD has exactly 30 snapshots in chain which is the > limit for XenServer. > > I tried to search for info why the chain can grow to 30 and only found > this article for CloudStack 2.2 > http://support.citrix.com/article/CTX133470 seems to be related. It > mentioned there maybe problem preventing XenServer from cleaning up > snapshots. However I can't find any more error info other than CS > Management log 'SR_BACKEND_FAILURE_109The snapshot chain is too long'. > > What can cause XenServer or CloudStack not cleaning up snapshots from > primary storage? Thanks in advance. > > Yong > -- Regards, Kirk Jantzer c: (678) 561-5475 http://about.met/kirkjantzer
