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

[Matthias Thyroff]

On 22.11.2013 23:21, gareth.glaccum at btopenworld.com wrote:
>
> 1) How often does it happen/how easy is it to reproduce?
>
Well, not really. Maybe once / three days? I do not know when it starts, 
I only know when I realize (or get complaints about) hanging frontends.

> 2) What process is the one that causes the 100% CPU load on the backend?
>
the mythbackend process. killing the mythcommflag process does not fix it.

> Recently I found that I had a slight misconfiguration, and a 
> mythcommflag was trying to do it over the network, rather than local 
> disk. Caused all systems to go slow.
> Double check your  interface speeds too, turned out that my problem 
> was compounded by one of my Gb interfaces going half duplex
>
> Don't know how the ubuntu systems configure their SQL databases, but 
> if it is done right 2GB should be bad for what myth wants to do.
>
I will identify the space hogs and clean them up. It looks like 
recordedseek is the biggest one, 255MiB, credits with 90MiB second and 
oldrecorded the third with 13MiB. Not that much, either, now that I look 
at it.

> If it is easy to reproduce, then I would unfortunately recommend 
> taking a backup of the database, and clearing it. Personally I suspect 
> that there might be an issue with the channel list. If you want to go 
> half-way, I would go to the mythtv-setup and clear all the channels, 
> then re-scan. EIT can issues on satelite are common, they move the 
> channels so frequently, however, sometimes they also tweak channels 
> which are good and are recorded from (Channel 4 gave me a headache). 
> HOWEVER, this might cause schedules which are locked to specific 
> channels to be need to be reset.
> On my system, when I added a secondary channel source part-way through 
> the 0.27 development cycle, recording schedules which were set to 
> record on "BBC 1" would only record on the original channel source, 
> not the added ones.
>
I will try and clear the channel table by hand. Re-Scanning is really no 
option I want to consider because of the hassle of editing the channel 
list. As scanned, it is unusable. BTW, it is european Astra, they do not 
move channels around that much - at least the once I am using... but 
yes, the crap ones (erotic, shopping, ideology, ...) which maybe use EIT 
might be changing some more. Deleting that part of the channels table 
should be a good test.

> I could also be that the tuner card might be getting flakey..... 
> difficult to diagnose that on a 'production' home setup with 
> non-hotplug cards.

Sigh. That would be bad. Really hard to diagnose. The fact that until 
now, when the backend process was at 100%, there is a mythcommflag 
process running, makes that worth a consideration, though. Today I also 
had the first missing recording in years, but I thought more that it is 
because of the 100% cpu load of the backend process. Well ok, diagnosing 
would maybe not be so hard, I have two cards and I suppose I could live 
with one for some days.

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Thanks for your reply! I will make some more tests before I erase 
everything.

Regards,

Matthias