Backup methods

[Andrew Morgan]

On Fri, 11 May 2018, Anatoli wrote:

>> There may be an argument that could be made for 2 backup stratagies
>
> That's the point. In the context of SME environments (Small and Medium-sized 
> Enterprises, i.e. from 5 to 50 employees normally, up to 250 in some 
> countries) that we were talking about, a replication is an overkill, IMO. But 
> for large enterprises like MNCs, large universities, public mail providers 
> (Fastmail) of course multiple masters and backups via replication is the way 
> to go. For large deployments there are good backup solutions in Cyrus, but 
> for the small businesses admins I don't know any to recommend.

Anatoli,

I think you're making this harder than it needs to be...

For a small system with a few hundred mailboxes, a simple unix filesystem 
backup is sufficient.  You can dump the Cyrus mailboxes.db to a flat file 
every hour with cron (keep a few days worth).  Backup everything with your 
regular backup system (tar, rsync, etc).

If you suffer a complete loss of the system and have to restore from the 
backup, you won't care much about a few database file inconsistencies, 
which can be repaired with Cyrus' reconstruct tool.  You would recover the 
whole backup, recover mailboxes.db from the most recent flat file export, 
and then run reconstruct on every mailbox.

If you need to recover some messages or mailboxes that were deleted by a 
user, then just recover those individual files or directories from you 
backup.  Run reconstruct -rf on the mailbox.

Naturally, delayed expunge and delayed delete are fantastic ways to avoid 
all this work.  Purge them only after a few weeks or a month has passed. 
It is much easier to restore using those delayed delete/expunge features.


Thanks,
 	Andy