dovecot - Jul 2012 - mdbox with separate index location results in many emptydirectories

Hallo,

I use dovecot 2.1.7 with mdbox format and I specified a separate  
location for mailbox index files with

mail_location = mdbox:/dovecot/storage%h:INDEX=/dovecot/index%h

With this setting I get for every mailbox a directory under both  
filesystems /dovecot/index and /dovecot/storage, e.g. for the inbox it  
looks like that:

# ls -lR /dovecot/index/home/hrz/myuser/mailboxes/INBOX  
/dovecot/storage/home/hrz/myuser/mailboxes/INBOX
/dovecot/index/home/hrz/myuser/mailboxes/INBOX:
total 49
-rw-------   1 myuser     hrz        20480 Jul 20 11:12 dovecot.index.cache
-rw-------   1 myuser     hrz         1280 Jul 20 08:00 dovecot.index.log
-rw-------   1 myuser     hrz          301 Jul 19 16:45 dovecot.index.search
-rw-------   1 myuser     hrz           20 Jul 19 16:45  
dovecot.index.search.uids

/dovecot/storage/home/hrz/myuser/mailboxes/INBOX:
total 3
drwx------   2 myuser     hrz            2 Jul 19 15:20 dbox-Mails

/dovecot/storage/home/hrz/myuser/mailboxes/INBOX/dbox-Mails:
total 0

As expected the index files now reside under  
/dovecot/index%h/mailboxes/, but the path  
/dovecot/storage%h/mailboxes/ also contains for every user and every  
mailbox name a directory which in turn contains only an empty  
subdirectory 'dbox-Mails'.  These directories seem to me to sum up to  
a lot of unneded infrstructure objects. I tried to delete these empty  
directories, but dovecot did not like that and stopped to work. So  
somehow they are necessary, in spite of setting a separate index file  
location.

So my question is, could these empty directories be avoided, perhaps  
in a future version?

Greetings,
Juergen

-- 
Hochschulrechenzentrum der | Mail: Juergen.Obermann at hrz.uni-giessen.de
Justus-Liebig-Universitaet | WWW:  http://www.uni-giessen.de/obermann/
Heinrich-Buff-Ring 44      | Tel:  0641-99-13054 (0641-99-13001)
D-35392 Giessen, Germany   | Fax:  0641-99-13009

On 20.7.2012, at 15.46, J?rgen Obermann wrote:
> mail_location = mdbox:/dovecot/storage%h:INDEX=/dovecot/index%h
..
> As expected the index files now reside under /dovecot/index%h/mailboxes/,
but the path /dovecot/storage%h/mailboxes/ also contains for every user and
every mailbox name a directory which in turn contains only an empty subdirectory
'dbox-Mails'.  These directories seem to me to sum up to a lot of
unneded infrstructure objects. I tried to delete these empty directories, but
dovecot did not like that and stopped to work. So somehow they are necessary, in
spite of setting a separate index file location.
> 
> So my question is, could these empty directories be avoided, perhaps in a
future version?
No plans to do it. The empty directories under /dovecot/storage are used to find
out what mailboxes exist. And in some setups those directories aren't always
empty (e.g. dovecot-acl files go there).