Re: BUG: xfs on linux lvm - lvconvert random hungs when doing i/o

[Stanislaw Gruszka <stf_xl@wp.pl>]

On Friday 21 March 2008, Josef 'Jeff' Sipek wrote:
> On Fri, Mar 21, 2008 at 03:20:16PM +0100, Stanislaw Gruszka wrote:
> 
> Interesting, I've noticed similar hang (based on my un-expert inspection of
> your backtraces) which went away as suddenly as it appeared. I wasn't making
> snapshots or any other LVM operation at the time. It just happened - logs
> didn't contain anything.

What I showed in traces is real deadlock, processes will stay in this state
as long as machine power off or end of the world, nothing will up semaphores.

Making snapshot when there is pending I/O on volume take much more
time compering when there is no load, propably because of locks contention,
which is problem by itself.  However in most cases processes unlock
after some time. For me making snapshot take few seconds without I/O
and something between 1 - 3 minutes with I/O . However, as I told before,
in very rare cases making snapshot with I/O on xfs volume take forever.

Stanislaw Gruszka