hello all,
I would like to enable LVM to backup opened files on a Ubuntu 12 server. Anyone can tell me if is I can use LVM even on a basic ( not LVM ebnabled ) partition?
BR Stefano
Hmmm… I’m not a Linux expert my GUESS is that if you don’t have LVM enabled (or aren’t running Duplicati as root) then the --snapshot-policy setting probably won’t help. 
This setting controls the usage of snapshots, which allows Duplicati to backup files that are locked by other programs. If this is set to “off”, Duplicati will not attempt to create a disk snapshot. Setting this to “auto” makes Duplicati attempt to create a snapshot, and fail silently if that was not allowed or supported (note that the OS may still log system warnings). A setting of “on” will also make Duplicati attempt to create a snapshot, but will produce a warning message in the log if it fails. Setting it to “required” will make Duplicati abort the backup if the snapshot creation fails. On windows this uses the Volume Shadow Copy Services (VSS) and requires administrative privileges. On Linux this uses Logical Volume Management (LVM) and requires root privileges.
Default value: “off”
Correct, the snapshot policy will only work on Linux if you’re backing up files on a partition configured with LVM. So existing partitions that aren’t using LVM do not work.
To be clear - backups can still run on non LVM partitions, they just won’t be able to back up OPENED (in use) or otherwise locked files (EVEN if running as root).
Yup, I run Duplicati on ZFS without snapshot policy. As far as I know it will work on any files Linux can read, it just won’t do snapshots unless it’s on LVM (probably as root).
Are you sure about that? I have never been able to NOT open a file as root, even if it’s open by another process. Linux doesn’t lock files in the same way as Windows.
Only as sure as the bolded part of the parameter description. 
lol… well LVM definitely has a snapshotting ability, and maybe it will quiesce the filesystem. But snapshots are not required on Linux to back up open files. I do not have the snapshot policy configured on my Linux system and Duplicati has never given me a warning about locked files.
Well I’ll certainly defer to you as I’ve only got a small Linux backup going against unopened files.
thanks to all for your help,
since my disks are not configured in LVM, I will only use backup without configure --snapshot-policy.