On Tue, Apr 17, 2012 at 10:19:45AM +0200, Stefan Priebe - Profihost AG wrote:
> Am 17.04.2012 01:56, schrieb Dave Chinner:
> > Your first question should be: is this a known problem?
> > And the answer to that is: I don't think so.
> Sorry absolutely correct.
> > So, is the system actually hung?
> No. The kernel has ended the stalled request.
> > Were there IO errors around this time?
> > did the system recover and continue to work normally?
> > What's your storage hardware, application, workload, etc?
> It a Raid 10 of 1TB SATA Drives in front of a 3Ware Controller doing
> heavy rsync backups.
Hmmm. It sounds like it is just taking a long time for the IO to
complete, not that there is any other problem. If the IO is realy,
really slow, the a log force is definitely a place it coul dstall
for some time.
Does the RAID controller have a BBWC? What IO scheduler are you
using? Does mounting with nobarriers reduce the stall time? Can you
reduce the IO load so that it doesn't end up in this state?