Current thinking on backups ?

deano-dovecot at areyes.com
Sat, 30 May 2020 02:34:56 -0000

I run a pair of dovecot servers for personal small domains with several
layers of backup in place ...

- The two dovecot servers replicate to each via a Tinc vpn mesh. That
gives email resiliency.
- All mail is replicated via offlineimap to a 3rd server over that Tinc
vpn. It's on the mesh, it has space, so why not ?
- All mail is replicated as well as via mbsync to a zfs dataset on my
main media server at home once an hour.
- That zfs dataset (and others) is snapshot'd hourly, and zfs send/recv
to a backup box nightly.

Outside of dovecot procedures, I find mbsync to work extremely well.  It
was easy enough to set up a systemd timer and service to pull the mail
down.


mysync.timer
===========# Run the mbsync process to sync mail down to local mediabox

[Unit]
Description=mbsync timer
ConditionPathExists=%h/.mbsyncrc
ConditionPathIsDirectory=/stuff/Backups/Mailsystems/mbsync-backups

[Timer]
OnBootSec=15m
OnCalendar=hourly
Persistent=true

[Install]
WantedBy=timers.target


mysync.service
=============# mbsync service

[Unit]
Description=mbsync backup from mailsystems
ConditionPathExists=%h/.mbsyncrc
ConditionPathIsDirectory=/stuff/Backups/Mailsystems/mbsync-backups

[Service]
Type=oneshot
ExecStart=/usr/local/bin/mbsync backup

[Install]
WantedBy=default.target


"backup" is the mbsync group that includes all the defined channels
that
determine what should be backed up.  Transparent.  In the background.
Don't have to think about it, it's just there.

I've done test restores to test environments via mbsync, and it all
works flawlessly.


On 2020-05-26 12:31 am, Germain Le Chapelain wrote:
>> Le 24 mai 2020 ? 14:42, Laura Smith
>> <n5d9xq3ti233xiyif2vp at protonmail.ch> a ?crit :
>>
>> Hi,
>>
>> What are people doing for backups ?
>> My current process is LVM snapshot and backup from that to NFS share.
>> But there seems to be hints around the internet that people use/abuse
>> "doveadm backup" for backup purposes even though it seems its
original
>> intention was for transferring mailboxes between dovecot instances.
>> Assuming its ok to "doveadm backup" to an NFS share, is it ok
to use
>> "doveadm backup" when dovecot has replication setup
>> (replication-notify etc.)  ? Or will it interfere ?
>> Thanks!
>> Laura
>
> This has came up in the past:
>
> https://dovecot.org/pipermail/dovecot/2020-February/thread.html#118206
>
> I ended up developing my own system based on forwarding all emails to
> a program (from which I back-up as they come in.)
>
> I am hoping if disaster and/or misfortune were to strike my server, I
> could simply cat >> back all those files in order (or not come to
> think of it) in the /var/mail/<username> (or somewhere even better
fit
> in Postfix.)
>
>
> I am not interested in saving the state of the mailbox as much as all
> the mails that ever come in (or go out.)

--
Dean Carpenter
deano is at areyes dot com
203 six oh four 6644