[Dovecot] Setting location for indexes

[dovecot.7.signal11 at spamgourmet.com]

> > dovecot: IMAP(uid): fstat() failed with file /home/uid/mail/.imap/INBOX/dovecot.index.log: Stale NFS file handle
> 
> > (a) why can't it just close the file and re-open ?
> 
> NFS has issues with files that are open on one client, and get deleted on
> another. UNIX systems require that files don't disappear while they are in
> use, but NFS is stateless and it simply can't know when a file is in use.
> The result is the 'stale NFS handle' kludge, which also prevents a simple
> close-and-open. Don't use index files on NFS disks.

First, the file did not disappear - the NFS is flaky under high load, that's
all. Closing and re-opening the file would probably fix the issue, at least
after the traffic spike.

Second, these are files that are intended for dovecots internal use only. If the
NFS filehandle goes stale, it's anyway highly unlikely that someone else has 
deleted them, and dovecot should know that - IMHO it should at least try to recover. 

Third, I'm perfectly willing to put the index files on a local disk, but I need
dovecot to autodetect the rest of the mail environment, unless I want to define
it completely for each user individually, and apparently dovecot does not let
me do that(?).

>From the (few) answers I got so far, it seems that it is in fact impossible
to specify 'default_mail_env = INDEX=/var/spool/mail/INDEX/%u', so would
anybody know where in the sources the root directory for the indexes is set,
such that I can patch the code?