What methods exist for backing up Xen virtual machine contents? I have some virtual servers running on LVM / Ext4 disks. Preferably a method which can be directly executed over SSH / network connection without the need of creating a local duplicate of virtual machine first.
As far as I am concerned I'd like to back-up the disk image only, not the running state. However, simple copy of the disk partition on-line will probably yield to Ext4 corruption?
As far as backing up instances go... 90% of the time... it's no different than backing up a physical server. You can simply rely on good ole' tar & other similar backup tools... (my preference is BackupPC lately... just make sure to make use of "dm-snapshots" that will let you make a snapshot image while databases are momentarily frozen & such). I'm not 100% certain... but there are native tools in xenserver that would let you make a live-snapshot of the disks. I'm not 100% a fan of live-snapshots... as mysql & others might be in the process of updating the database when the snaphost is made... effectively making the files that are backed up corrupt... Better to freeze or shutdown the databases... then snapshot... then unfreeze/startup the server...