On Thu, Dec 22, 2011 at 3:49 PM, Stan Hoeppner stan@hardwarefreak.comwrote:
On 12/22/2011 8:08 AM, hydra wrote:
Hello Timo, thank you for the reply. I was suspecting the same. However:
- the machine runs under Vmware,
- I've tried 3 different kernel versions,
- I've tried 3 different SCSI controllers.
All same results.
dmesg output? Log errors?
Nothing there
Is your EXT4 filesystem on a VMFS volume or an RDM (SAN LUN)?
VMFS
On Wed, Dec 21, 2011 at 6:16 PM, Timo Sirainen tss@iki.fi wrote:
On 21.12.2011, at 18.38, hydra wrote:
That's a kernel process..
I suspect, that this is something to do with Dovecot, because after deleting the dovecot.index.cache file, everything went back to normal. When this happens, I cannot unmount the drive nor a system reboot works.
System (host machine) reboot, or virtual machine reboot doesn't fix the problem? FYI, Linux doesn't unmount drives, it unmounts filesystems.
After the virtual machine reboot, the CPU usage is normal again, but just until doveadm is launched again (it was run from cron). Sorry for the partition/drive terminology mess up.
I'd say you may have a problem with your VMFS volume or RDM, or maybe just your EXT4 filesystem. Have you run an fsck on it? What result?
A normal system reboot wasn't possible, because the ext4 fs wasn't unmounted (and it wasn't possible to unmount the fs nor run sync - both locked up) and thus I had to reboot from the vSphere Client. After the reboot, fsck placed the fs to a consistent state, however the problem occurred the next morning, when doveadm from the cron was run again. So a fsck didn't help.
Or, as Timo suggests, could be a kernel bug. Or an interaction of these low level layers causing a problem. If you can't unmount a filesystem, that has nothing to do with Dovecot, and points to a much larger, more critical, problem.
Do you have this problem when booting an older kernel? Say 2.6.32? 2.6.37?
The oldest available kernel is 2.6.32 so I'm going to test it.
Thank you :)
That's a kernel bug..
I think you're thinking it the wrong way: Dovecot isn't causing your system to break. Your system is causing Dovecot to break. Faulty hardware or faulty kernel.
-- Stan