[mythtv-users] After 7y5m running, time to start from scratch after update to .27?

Stephen Worthington stephen_agent at jsw.gen.nz
Wed Nov 27 00:46:07 UTC 2013


On Tue, 26 Nov 2013 20:44:56 +0100, you wrote:

>Hello Stephen, Geoff,
>
>thanks for the thought. I have switched now from the PCIe Intel NIC to 
>the onboard nic and I have exchanged the cable to the switch. Today, the 
>backends were behaving well, so I cannot say that that was the fix, it 
>has not gotten worse, either.
>
>What makes me doubt in the hardware/cable/bandwith (GB network, wired) 
>theory is that when it fails, it fails on one (maybe two, I think I also 
>saw failing two) entries in the recorded programs list. It fails in 
>showing the thumbnail and in showing the "recording available" sign in 
>the list (i.e. it shows the little grey cross). This one entry fails, 
>"mythcontext: backend is online", this item comes back, "mythcontext: 
>backend is online", fails... and goes on like that.
>
>My system does not fail on streaming gigabytes of HD content. It never 
>fails in showing the programming information or anything else, Only in 
>the recorded programs list view, and there, only in one item (random, 
>not specific). I also doubt it is access to the recordings directories.
>
>When I start to watch the failing recording, it might take long (5-10 
>seconds?) until the recording starts showing, "mythcontext:..." message 
>(popping up every few seconds for quite some time, then the messages 
>stop.) Once the recording streams, it is not jerky or anything, 
>independantly from the message popups.
>
>I once fixed the failing situation by deleting the program description 
>from the recorded table in phpMyAdmin. But then, it normaly fixes itself 
>at some point, too.
>
>It is something else. Maybe mysql, or it fails on accessing the fanart 
>background images which are new (in my setup) since 0.27. (also fails to 
>show in the failing situation)
>
>Or the schema. Or a bug. Maybe it is related to the xmltv data in the 
>end. Since some time, I get really long descriptions, and sometimes, 
>wrong encodings in the myth database (even though the original data 
>downloaded by xmltv is correct).
>
>I will keep looking. Thanks again for the support!
>
>Regards,
>
>Matthias

It certainly does sound like a pretty weird problem.  Reading the
above, I had a couple of ideas that might be worth trying.

First, you might like to rule out something related to displaying the
artwork.  You can do that by modifying your theme to not display
artwork, so it will still be downloaded and can be used again by
swapping back to the unmodified theme.  I have just been modifying my
MythCenter-wide setup - it is fairly easy now.  Just copy your theme
from /usr/share/mythtv/themes/ to /home/<mythtv login>/.mythtv/themes.
I also changed the name from MythCenter-wide to MythCenter-wide-JSW so
that I can go back to the original MythCenter-wide by just selecting
the old theme again.  You do that by changing the name of the
directory it is in, and also changing the theme name in themeinfo.xml
file.  Then you need to find all references to the artwork in the
other files and remove them.  Zig has already done the hard work on
that and provided a couple of us with copies of his changes by direct
email - see this thread:

  http://www.gossamer-threads.com/lists/mythtv/users/558332

so you might just like to ask him for a copy.  Once your new theme is
set up, you just use Setup > Theme Chooser to select it and to go back
to the original theme.

I would also suggest checking on where you are storing the artwork -
the default location in Mythbuntu is in
/var/lib/mythtv/[banners,fanart,coverart] which is normally on your
system partition, so you can find that all the new artwork downloads
are filling up your system partition - and a full system partition can
cause any number of nasty problems.  I personally think that if you
are downloading artwork, it is a good idea for the artwork storage
groups to be pointed to a recordings partition where they will then
always get enough space as MythTV will expire recordings to make
enough room as the artwork grows.

My next thought was, are you having disk problems somewhere?  Is one
of your disks giving problems where it times out and retries?  That
might explain why it only happens on some recordings.  Do you have
smartd (smartmontools package) installed and monitoring your hard
drives?  Is it set up to send you alert emails if anything is going
wrong?  Are any drives showing errors in their SMART data or in their
SMART logs when you run smartctl?  Bad disk errors with retries should
also show up in kern.log and syslog, even if smartmontools is not
installed, as the resetting of the drive will be logged.

If the problem is disk related, it is likely to be just one disk, so
when it happens, you might like to go to the recording in the list and
hit the I key (or the same on the remote) twice and scroll down to
find the filename of the file for the recording, then search for that
filename and find the drive it is on (use the locate command if the
file is older than one day old).  If the files that are causing
problems are all on one drive, that would be a big hint.


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