[mythtv-users] Fedora help needed: Hard disk access is sometimes
slow (DMA is on)
dctanner at gmail.com
Sat Sep 11 06:50:42 EDT 2004
Try using nice on mythfrontend. I think it fixed a few of my
occasional prebuffering pauses.
On Sat, 11 Sep 2004 08:24:32 +0200, Thomas Börkel <thomas at boerkel.de> wrote:
> My Myth box worked like a charm from february until about 3 weeks ago.
> Now I get occasionally stuttering video during playback (mythfrontend
> says "prebuffering pause". I also have some strange entries from
> mythbackend (IOBOUND - blocking in ThreadedFileWriter::Write()) and the
> scheduler today took 19 seconds to schedule where it normally takes 0.5
> These effects are not all the time. They come and go. When it happens,
> the HD LED blinks very bright (= quick) during accesses.
> For example, during playback, it normally blinks only with short
> flashes. But when it happens, it looks like multiple threads would
> access the HD. When I press pause, blinking stopps completely, so there
> is no other process accessing. Resuming playback results in heavy
> blinking again. This lasts for a minute or two, then it's back to normal
> Sometimes, starting mythfrontend is quick as usual, sometimes it takes long.
> hdparm tells that DMA is on (udma4) and that it's fast (60 MB/s with -t).
> top tells that there is nothing unusual going on and there is very
> little swap space used.
> I also found nothing unusual in dmesg or /var/log/messages.
> There are no interrupt errors in /proc/interrupts.
> I am not aware that I changed anything that could be related.
> May-be related info:
> - one box for frontend and backend (installed using Jarod's guide)
> - root filesystem is ext3
> - filesystem for recordings partition is XFS
> - using NVidia (4363) TV-out with XV
> - commercial flagging is OFF
> - Myth 0.15.1
> - Fecora Core 1
> - Kernel 2.4, 2197
> - ivtv 0.1.10pre2 ck36c
> - 512 MB RAM, Celeron 2.6 GHz
> Anyone any hints?
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> mythtv-users at mythtv.org
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