On Dec 8, 2014, at 8:33 AM, John wrote: > Hello list, > > I have a few questions about creating backups to be stored offsite. > > If a guest is running, can I compress the image without it becoming > inconsistent? If not, can it be copied without it becoming inconsistent? > By inconsistent, I mean will I see weird effects and broken files if the > backup is restored? Previously I've shut the VM down to avoid this, > before archiving. > > I have each image on its own (external to the image) ZFS filesystem. > Internally the image is using ufs if freebsd, ext3fs if linux. Would > using some ZFS method of duplication be better? In this case, would the > image become inconsistent? > > Basically, what I want to do is to run accurate backups without shutting > down and restarting the VM. Is this possible? If it isn't, I think the > only alternative is to make a script that shuts the vm down, copies it, > restarts the vm then runs its compression and backup-over-ssh routine.
[[ adding [email protected] in case I'm wrong ]] If you are using UFS internally to the VMs then you'll need to send a snapshot that is consistent. If you are just copying the files out from under a running vm you are going to get spaghettios for a filesystem if you try to recover as you need a true point in time snapshot. I think a few better options would be: 1) Inside the VM create a UFS snapshot then dump that externally using tools. 2) Create the UFS snapshot, then make sure that the file/vzol is snapshotted using zfs. 3) Just snapshot the underlying zvol you've made the UFS image on and send that (you'll get a dirty FS on restore, but it *should* be recoverable with a simple fsck) 4) Use zfs internally to the vm and send/receive the internal zfs. option 3 is the least safe imo as you can wind up with filesystem "angry". in case 1 and 2 you'll have UFS snapshots that should be "OK" to restore from. in case 4 you are also doing snapshot, but you switch to ZFS. -Alfred _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization To unsubscribe, send any mail to "[email protected]"
