[Dovecot] dovecot.index.cache 1/3rd of INBOX size

[Timo Sirainen]

On Fri, 2005-06-17 at 12:41 +0100, Chris Wakelin wrote:
> > Fixed in CVS. The mails weren't being marked as deleted in cache file 
> > because of a simple mistake ("!=" -> "=="). So after the change the 
> > files still won't get compressed immediately, but it'll work in future.
> 
> Thanks! I've applied the fix (I think!) to dovecot-stable-20050617 and 
> am now using it. 

I should probably backport that too..

> My dovecot.index.cache is 5MB or so at the moment, and 
> still seems to be growing, even when I delete lots of old messages. 
> Presumably there needs to be 20% "deleted space" before anything will 
> happen.

Right. so you'll need to grow and delete 1MB more :)

> Does it ever rebuild the cache from scratch in normal operation? What 
> happens if a non-dovecot process deletes messages, do they ever get 
> removed from the cache?

The external process doesn't delete the mail from dovecot.index file, so
Dovecot notices that it got deleted and deletes it from index and from
cache.

> Lastly, do you have a tool or utility to analyse the cache files so I 
> can see how many messages/headers and how much "deleted space" there is? 
>   "strings" isn't too reliable an analysis method ;)

Not really.. Wouldn't be too difficult to implement using mail-index.h
and mail-cache.h APIs though. Any volunteers? ;)

The cache file anyway heavily relies on index file. Without that there's
really know way of knowing what parts of the file belong to which mails
(or deleted mails).