On Thu, Dec 22, 2011 at 3:49 PM, Stan Hoeppner <s...@hardwarefreak.com>wrote:
> 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 <t...@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 > >
