[Dovecot] Dovecot altmove questions

[Timo Sirainen]

On Mon, 2012-02-27 at 01:07 +0100, Maria Arrea wrote:
>  1º General mdbox question. We are happy usings zlib_save, but we
> would like to try bzip2 compression. Can we change zlib to bzlib
> without problems? In other words, can we mix & match gzipped and
> bzipped messages in the same mdbox file ?

Yes.

>  2º With doveadm altmove we can move messages matching a pattern to
> alternate storage. I have read an older post in this mailing list
> about passing specific mdbox options to doveadm altmove. Should be a
> good idea to have a "main" mdbox area with zlib 9 and mdbox_rotate=1d
> and mdox_rotate_size=60m and an "alternate area" with bzip9,
> mdbox_rotate=1 week and rotate_size > 60 MB? In the alternate area
> should only be "old" mail (1 year older).

I guess it makes sense.

>  3º We have separate raids for indexes (raid 1+0) and mdboxes (raid
> 5). We have almost 3 TB of gzipped mdboxes, and our backup (bacula) is
> taking almost 16 hours to make a full backup. Our main problem is that
> indexes are backupd hours before mdboxes, and that bring us some
> inconsistencies. What is the "right" way of backing up for separate
> indexes and mdboxes?

The eventual solution is a Dovecot backup agent, but for now I guess
there isn't anything better than taking filesystem snapshots.