[Dovecot] Very High Load on Dovecot 2 and Errors in mail.err.

[Timo Sirainen]

On 11.6.2012, at 11.09, Jesper Dahl Nyerup wrote:

> Stracing the processes in D state from before they hang has just
> revealed something interesting, however, pointing to an issue with
> inotify rather than epoll.
> 
> [snip]
> [...]
> 15414 23:27:36 inotify_init()           = 12 <0.000024>
> [...]
> 15414 23:27:36 close(12 <unfinished ...>
> 15414 23:28:51 <... close resumed> )    = 0 <74.593917>
> 15414 23:28:51 close(9 <unfinished ...>
> 15414 23:28:51 <... close resumed> )    = 0 <0.000080>
> 15414 23:28:51 exit_group(0)            = ?
> [/snip]
> 
> In short, as far as we can tell, all the processes in D state appear to
> be waiting to close the file handle they got from their inotify_init(),
> and eventually all these close()s go through almost simultaneously.

Yeah. Looks like a kernel bug. You could try if it goes away by disabling inotify in Dovecot. Either recompile with "configure --with-notify=none" or maybe you can disable inotify globally with:

echo 0 > /proc/sys/fs/inotify/max_user_watches
echo 0 > /proc/sys/fs/inotify/max_user_instances