[pve-devel] New Backup Strategy - pve-manager patch

[Jeff Moskow]

See my responses inline.

On Mon, Jan 20, 2014 at 06:30:43AM +0000, Dietmar Maurer wrote:
> >   1.  Allows idle machines to be skipped if they have already been backed up
>
> This looks dangerous to me.

It shouldn't be.  If a VM hasn't been turned on (idle), then nothing should have changed
and the backup should be fine.  I guess that some of the configuration information could
have changed, but if that's concern, I could also check the date on the .conf file (probably
not a bad idea).

>
> >   2.  Allows multiple storages to be assigned to a backup job and for vzdump to
> > pick the best place to store a backup
>
> Why do we want/need that? An what exactly is the 'best' place?

We want it because we rotate backups across multiple backup storage devices and if/when
a backup fails, we used to end up removing our most recent backup rather than the oldest
one.

The best place is defined as follows (calculated per VM):

        1) for all strategies, if there is a storage with no backup, use that
        2) for distribute, aggressive, fill find a storage where the most recent backup on that storage is older than the most recent backup on all others
        3) for always, replace the oldest backup no matter which storage it's on

Jeff