[Dovecot] Compressing existing maildirs

[Dovecot-GDH]

The cleanest (though not necessarily simplest) way to go about this would be to use dsync to create a new maildir and incrementally direct traffic to a separate Dovecot instance.

Unless you have a legacy application that relies on maildir, switching to mdbox would be a good idea too.

I expect that with Dovecot compression is something that can "just be turned on", but for fear of any possible issue, I chose to migrate mailboxes in batches with the way mentioned above.

On Dec 24, 2011, at 7:20 AM, Jan-Frode Myklebust wrote:

> I've just enabled zlib for our users, and am looking at how to compress
> the existing files. The routine for doing this at
> http://wiki2.dovecot.org/Plugins/Zlib seems a bit complicated. What do
> you think about simply doing:
> 
> 	find /var/vmail -type f -name "*,S=*" -mtime +1 -exec gzip -S Z -6 '{}' +
> 
> 
> I.e. find all maildir-files:
> 
> 	- with size in the name ("*,S=*")
> 	- modified before I enabled zlib plugin
> 	- compress them 
> 	- add the Z suffix
> 	- keep timestamps (gzip does that by default)
> 	
> 
> It's of course racy without the maildirlock, but are there any other
> problems with this approach ?
> 
> 
> -jf