rmdir() EBUSY warnings on 2.2.12

[Timo Sirainen]

On 4.7.2014, at 1.30, Giel van Schijndel <giel+dovecot at mortis.eu> wrote:

> I'm getting a lot of syslog spam on FreeBSD 10 from
> nfs_flush_file_handle_cache_dir where, apparently it tries to rmdir()
> the mountpoint of my mail storage.
> 
>> Jul  4 00:04:44 mailhost dovecot: imap(user at example.com): Error: nfs_flush_file_handle_cache_dir: rmdir(/var/mail/vhosts/example.com) failed: Device busy
> 
> We're using ZFS and have /var, /var/mail, /var/mail/vhosts,
> /var/mail/vhosts/example.com and /var/mail/vhosts/example.com/user as
> separate ZFS datasets (to enable per-user and per-domain snapshotting).
> 
> So apart from NFS flushing being unnecessary (ZFS != NFS) I'm not really
> sure why using rmdir() for another directory than the Maildir specified
> in mail_location is a good idea. I.e. given that Maildirs shouldn't ever
> be emtpy (cur,new,tmp) anyway.

Don't set mail_nfs_index=yes or mail_nfs_storage=yes and Dovecot won't try these kludgy things to flush NFS caches. They don't fully work anyway and they are highly discouraged for any kind of use, ever. Mainly they exist for backwards compatibility.