[mythtv-users] mythbackend crashes

[glen martin]

On Wed, 2004-11-17 at 12:13, Buchanan, Paul (West) wrote:
> On Wednesday, November 17, 2004 1:20 PM,
> mythtv-users-bounces at mythtv.org wrote: 
> > On Tue, 2004-11-02 at 14:33, Andrew Plumb wrote:
> >> --snip--
> >> 2004-11-01 22:29:27 IOBOUND - blocking in ThreadedFileWriter::Write()
> >> 2004-11-01 22:29:28 IOBOUND - blocking in ThreadedFileWriter::Write()
> >> --end-snip--
> > 
> > I've had three crashes  in the past 24 hours like
> > this.  In only the third case could I read any
> > console output, and in that case, after the IOBOUND
> > message I got (paraphrased):
> > 
> <snip>
> > 
> > For the record, I'm using XFS for video files,
> > ext3 for some other partitions, software raid,
> > no partitions over 60% full.
> 
> 
> My .16 backend will hang (no segfault, just stops responding) with IOBOUND messages when my XFS /video partition reaches around 90% full.  I see that you are only 60% full, but thought I'd comment anyway.  XFS has a tendency to drastically reduce in performance as the partition fills up.  Although I thought I could live with keeping my partition 85% free, I may end up switching to ext3 to avoid the instability.  You may want to investigate your file system performance, as the Backend seems unhappy when slowdowns occur.

This is interesting, in that I've got the lvm and raid
in between the backend and the real disc. So cpu challenges
become filesystem bandwidth problems. Hrrrm. Need to rethink
this perhaps (or make damn good and sure I never get close
to pegging the cpu). May be implications for transcoding
(which I'm not doing presently, but likely will in future).

My larger concern though is the overal system hang when
this happens. If only the backend hangs or crashes,
yes I miss some TV. But the overall system hanging,
that's a problem.  This symptom's gotta be a driver
problem though, doesn't it? So probably more than one
issue overall.

glen