[mythtv-users] TFW, Error: Write() -- IOBOUND ..... and mythbox crashed

[Ma Begaj]

I was thinking about changing a file system type. I am using ReiserFS
for years, but I never had 3 tuners and 3 recordings running at the
same time.

I could move my recorded data to a file server, change ReiserFS to XFS
(should better handle big files) and copy the data back again. What do
you think about it? Maybe I could  turn on AAM after that, because I
do no like hearing my disks :)

M.


2007/10/18, Ma Begaj <derliebegott at gmail.com>:
> Thanks ...
>
> These both crashes occured when I am recording 3 three shows and
> watching/fast-forwarding a recording at the same time.
>
> I turned off AAM (Acousting Management) of the both disks to try to
> make them faster with:
> hdparm -M 254 /dev/hd[ab]
>
> Disks are louder and that is not optimal, but that might help.
>
> iostat -xk gave me most of the time something like this (AAM turned off):
> Device:  %util
> hda  11.35
> hdb  4.45
>
> avg-cpu:  %user   %nice %system %iowait  %steal   %idle
>           40.10    0.00    4.51    3.76    0.00   51.63
>
> Utilization never goes above 15%.
>
>
> I tried to fast-forward to recording which I am watching (during
> running 3 recordings at the same time) and fast-forwarding was not
> working so nice as usual (not fluent) and I got "Audio buffer
> overflow" errors in mythfrontend logs:
>
> NVP::AddAudioData():p1: Audio buffer overflow, audio data lost!
>
>
> Disk is doing pretty much ... 3 recordings, transcoding,
> fast-forwarding in a video... is that maybe just too much for these
> IDE disks? I hope not.
>
> But it is not crashing at the moment ... maybe turning off AAM helped.
>
> M.
> 2007/10/18, George Mari <george_mythusers at mari1938.org>:
> > Ma Begaj wrote:
> > > Hi,
> > >
> > > I had yesterday three recordings running at the same time (1x pvr150,
> > > 1x pvr500). At the same time, I was watching a recording. And suddenly
> > > my mythbox crashed and I had to reset it.
> > >
> > > I checked syslog and found nothing, but I found something in
> > > mythbackend log file:
> > >
> > > 2007-10-17 23:32:05.673 TFW, Error: Write() -- IOBOUND begin cnt(2048) free(835)
> > > 2007-10-17 23:32:10.724 TFW, Error: Write() -- IOBOUND end
> > > 2007-10-17 23:32:10.731 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> > > free(1095)
> > > 2007-10-17 23:32:10.735 TFW, Error: Write() -- IOBOUND end
> > > 2007-10-17 23:47:10.183 TFW, Error: Write() -- IOBOUND begin cnt(2048)
> > > free(1503)
> > >
> > > I checked the older mythbackend logs and I found more of these
> > > messages in the last few days, usually when I had 2-3 recordings (SD)
> > > running and watching at the same time.
> > >
> > > I have two IDE hard disks (2x 160GB WD) and 1GB single channel RAM.
> > > One of these disks has a system and home partitions and a partition
> > > for myth recordings. 2nd disk is only one partition for recordings.
> > > Everything is ReiserFS. I was thinking to change it to XFS these days.
> > >
> > >
> > > I run "hdparm -tT" and they are more or less the same for both disks:
> > > root at mythbox:/tmp# hdparm -Tt /dev/hd[ab]
> > >
> > > /dev/hda:
> > >  Timing cached reads:   1332 MB in  2.00 seconds = 666.17 MB/sec
> > >  Timing buffered disk reads:  136 MB in  3.03 seconds =  44.81 MB/sec
> > >
> > > /dev/hdb:
> > >  Timing cached reads:   1090 MB in  2.00 seconds = 545.26 MB/sec
> > >  Timing buffered disk reads:  172 MB in  3.02 seconds =  56.97 MB/sec
> > >
> > > not pretty fast? this
> > > http://readlist.com/lists/mythtv.org/mythtv-users/7/39724.html has the
> > > same problem, and the disks have two or almost three times higher
> > > "Timing cached reads".
> > >
> > > any ideas? I could buy new disk(s), but I think that these disks
> > > should be handle 2-3 recordings and 1 reading at the same time.
> > >
> >
> > You may be running into the limit of how many I/O operations per second
> > your single disk supports, as opposed to the bandwidth limit.
> >
> > If you have iostat, (part of the sysstat RPM on my FC6 installation) you
> > can run iostat -xk 2 in a shell while you are recording 3 streams and
> > watching another to get a picture of your I/O system.  The last column
> > gives you % utilization per device, and if it's at or above 100%, well,
> > there's your answer.
> >
> >
> > _______________________________________________
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> > mythtv-users at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> >
>
>
> --
> Glauben heißt nicht wissen wollen, was wahr ist ... Nietzsche
>


-- 
Glauben heißt nicht wissen wollen, was wahr ist ... Nietzsche