Questions around moving from 2.2.12 to 2.4.12

[Bron Gondwana]

On Wed, Feb 29, 2012, at 06:37 AM, Adam Tauno Williams wrote:

> > My goal is to migrate things over to a newer server running gentoo
> > linux, the maintained version of cyrus-imapd there is 2.4.12 (the older
> > 2.2.13 from a separate gentoo-overlay didn't compile for me).
> > Moving the mysql-DB shouldn't be much of a problem, the web-cyradm tool
> > runs on gentoo already
> > So my question is: how to move things in the most stress-free way
> > Could I simply copy over /var/spool/imap etc, and start the newer version?
> 
> Possibly, I'd rsync it, give it a try and see what happens.  I've moved
> from 2.3 -> 2.4 but haven't uses 2.2 in ages.

Make sure you get /var/imap or wherever the DB files are stored as well,
/var/spool/imap is just the emails - you want to keep the indexes!

> > Do I have to somehow convert things? If yes, is it problematic?
> 
> 2.3 -> 2.4 was pretty simple; worst part was the database upgrades
> [which took place automatically in-place]. They really grind the drives.

Your biggest risk is berkeley DB files.  If you are using berkeley,
either convert to skiplist first, or dump and restore.

Beware of mailbox sort order issues if you change that config.

> > I am thinking about just trying it for a test, but I would really feel
> > much better with some competent feedback from the cyrus-imap-community.

Trying is good :)  The upgrade itself should be clean, if slow - lots of
re-parsing of emails.  I looked into avoiding that, but it just made the
code really, really ugly as it tried to deal with different versions of the
index - so we decided to force the upgrade on first access.

Bron.
-- 
  Bron Gondwana
  brong at fastmail.fm