[Dovecot] Dotlock dovecot-uidlist errors / NFS / High Load

[list at airstreamcomm.net]

Timo & friends,

We have not posted in a long time regarding this issue, but I wanted to
update everyone that it was indeed an NTP issue.  We have since put
together stratum 2 servers on physical hardware (as opposed to virtual
machines) which now act as the source for our cluster of dovecot machines
and everything is working flawlessly.  I just wanted to give my thanks to
everyone that helped us trouble shoot this issue and show my gratitude for
such a great community!

Michael

On Fri, 28 Jan 2011 03:40:38 +0200, Timo Sirainen <tss at iki.fi> wrote:
> On Tue, 2011-01-25 at 12:34 -0600, list at airstreamcomm.net wrote:
>> 
>> Jan 25 11:30:11 1295976611 POP3(4eagles): Warning: Created dotlock
file's
>> timestamp is different than current time (1295976643 vs 1295976607):
>> /mail/4/e/4eagles/Maildir/dovecot-uidlist
>> 
>> We added the epoch time to the log_timestamp setting to compare it to
the
>> dotlock error, and as you can see the "Created dotlock" epoch time is
32
>> seconds in the future compared to the epoch time of the log event.  At
>> this
>> point I hope you can help us understand where a timestamp from the
future
>> might be generated from. 
> 
> The first timestamp comes from the .lock file's ctime as reported by
> fstat(). If that's in the future, then the possibilities are:
> 
> a) Bug in the kernel's NFS client code (unlikely)
> b) Bug in NFS server reporting or setting wrong ctime
> c) NFS server's clock went into future
> 
> No possibility of it being Dovecot's fault anymore.