[Dovecot] nfs locking issues...

[Aaron Wiebe]

A few questions...

1.  What are you running as the underlying FS for your NFS share?
2.  What are you using for the NFS server?
3.  Do you see any messages about lockd in your messages file?
4.  When you strace a deadlocked process, what do you see?
5.  Do these locks appear to deadlock on the same machine, or
     is one lock on one machine and another lock on another machine?

-Aaron

On Tue, Feb 26, 2008 at 11:03 AM, John Gray <gray at agora-net.com> wrote:
> I'm running Dovecot 1.1 RC1.  I believe I've done all the due diligence
>  for making things working correctly over nfs.  But I run into locking
>  issues if I run over nfs.
>
>  procmail is doing the delivery over nfs.  uw-imap was ruining over nfs.
>  dovecot is fine if its on the nfs server (i.e. it has local access to
>  the disk, no nfs)
>  I run into lock deadlocks if I run dovecot over nfs
>  Users are directed to different servers, but a given users will always
>  get the same server (at least until there's no activity for that user
>  for over an hour).  This only applies to when running dovecot over nfs.
>  Everybody goes to the nfs server otherwise.
>
>  Sometimes I can kill all the processes, remove the dot locks, and
>  recover.  Something I need to reboot the nfs server to recover.
>
>  Let me give a run down of the particulars:
>
>  All the mail is in mbox format.
>  everybody runs linux with kernel 2.6.24.2 (any known nfs locking issues
>  there?).
>  delivery is done via procmail, its locking and dovecot's are both
>  dotlock, fcntl.
>  The nfs mount options are
>  actimeo=3,hard,noatime,rsize=32768,wsize=32768,nfsvers=3
>  The clocks are in sync.
>
>  Dovecot.conf:
>  protocols = imap imaps pop3 pop3s
>  login_greeting = imap ready.
>  mail_location = mbox:~/:INBOX=/var/mail/%u
>  mmap_disable = yes
>  mail_nfs_storage = yes
>  mail_nfs_index = yes
>  protocol imap {
>  }
>  protocol pop3 {
>   pop3_uidl_format = %08Xu%08Xv
>  }
>  auth default {
>   mechanisms = plain
>   passdb pam {
>   }
>   userdb passwd {
>   }
>   user = root
>  }
>  dict {
>  }
>  plugin {
>  }
>
>  Any help would be greatly appreciated.
>
>  Thanks,
>  John
>
>  --
>  John Gray                           gray at agora-net.com
>  AgoraNet, Inc.                      (302) 224-2475
>  314 E. Main Street, Suite 1         (302) 224-2552 (fax)
>  Newark, De 19711                    http://www.agora-net.com
>
>