XO Backup Quiesce, VSS - confused
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Hi, I'm confused by different versions of documentation for XO, Xenserver etc. and concerned about the recoverability of XO backups of SQL and Exchange server VM's.
- Does an XO backup with advanced option "normal snapshot" use VSS to provide application consistency? I.e. does it use vm-snapshot-with-quiesce or a normal vm-snapshot?
- Some sources say the above only works with an additional installation step but it is unclear what that is, the one I found seems to be obsolete per: https://xen-orchestra.com/blog/xenserver-quiesce-snapshots/ If I do
vssadmin List Providersthe Citrix VSS does NOT appear. - https://xen-orchestra.com/docs/backups.html#consistent-backup says that quiesced backups (i.e. quiesced snapshots) are deprecated in favor of RAM-enabled backups. Much slower and larger. Is that the only or the best way to ensure apps can be restored without data corruption?
- What IS the recommended snapshot method, to ensure backups taken by XO are 100% safe, notably in the case of complex Windows apps like SQL and Exchange?
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- By default, Xen Orchestra will try to do quiesce snapshot, and falls back to normal snapshot if quiesce isn't supported/working.
- VSS is deprecated by Citrix, it will entirely disappear
- No, the other way to do it (and the easiest one), is to use "Offline backup" (ie it will shutdown the VM, snapshot, then start it just after, so the downtime will be small). We are also working on "blocking webhooks" for backups that will wait until the webhook is doing whatever needed (eg ask your Windows hosts to do what you want) and then start the snapshot
- The recommended way is to test your backups and adapt the strategy depending on those results
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@olivierlambert Merci!
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You are welcome!
