[Dovecot] FreeBSD NFS file locking mechanism

[Doug Council]

On Jun 21, 2007, at 7:56 PM, Tony Tsang wrote:
> I have some machines running FreeBSD and dovecot deployed. User's home
> dir is on NFS mount and I've found that dovecot only works with
> dotlock file locking mechanism, fcntl and flock failed. Now it causes
> problem with thunderbird (thunderbird is cachine connections) waiting
> forever and I noticed that dovecot is trying to acquire a lock but
> unsuccessful since the lock file is in place. Is it possible to use
> file locking other than dotlock on FreeBSD NFS mounted homedir? How do
> I achieve this?

I had a similar problem with NFS and dotlock contention with dovecot- 
uidlist on FreeBSD 6.2.  The problem is a long-standing bug in the  
FreeBSD NFS client.  If I remember right, when reviewing the code,  
dotlock is the only option for dovecot-uidlist.

I posted a workaround patch:

http://www.dovecot.org/list/dovecot/2007-May/022883.html

Not the best solution, but it is working fine on my setup.

-Doug