About backup
Ne backup is not bad but it lacks some features which are needed to have a relyable backup
most important the ability to backup offsite (nfs or another mounted drive) - i mean you can do that but the problem is what happens if that connection drops during backup
of course you can do backup on the same machine and later rsync or use another backup software to sync it away - still not the backupsolution we would need.
the community script have similar issues about relyability.
scripting is a fine thing but more complicated it gets more problematic it will be
none of the scripts have by default any kind of fallback or warning if for example storage on the offsite location is full or misses because of no connection
those things among some others have to taken into account even if your backup box is 5 meter aways form the zimbra device many things can happen (broken switch, full/damaged disk, changed firewall and so on)
so i recommend a real active client / server backup solution.
i do not recommend produtcs here but there a lot out there - if you got a tape backup server and wanna stick with opensource software you can give bacula a shot
i personally use for ne ans oss versions our onlinebackup software because it do excalty whats needed
it reconnect on fail for a time
it reports back everytime also in case of a fail
it encrypt and compress bevore upload
and more important i can reduce downtime with several backups a day because of using one datapool and infile deltas
to make a real backup you need to shutdown zimbra (oss) NE version can do without if you use the ne backup solution
so what i do is i make several hot backups (they are not usefull but they upload most of the data) and one cold
that way i got a downtime of 3.5 minutes for a hole cold server backup even if i have 5 or 10 gig more data
also the steady reports are very important - with a filter in zimbras inbox i see them only if it fails - if its ok they are in archive
downside is they are not per user level backup -
so if i want to restore a single mailbox ife to restore lates backup on a virtual host start zimbra there - extract by rest the mailbox and upload it to the real zimbra server
but this works
ife also an ne server but i do not longer use the backup there simply because ife to reduce the amount of data
double and tripplebackup make no sense just to restore one mailbox a month a bit easier...
of course its always a thing about amount of data we are talking about.
btw bevore you find your solution you can simply copy hole zimbra while running - then shutdown - recopy and overwrite only different files - (or do that with rsync) just to have at least anything with minimum downtime
which you should do bevore any update of zimbra anyway