My mythTV Backedend is an Intel quad core 2.4 with 4GB of G.Skill RAM. A vanilla GigaByte motherboard in a fairly nice looking case with 2TB of disk. I use a pair of HVR-2250’s to record digital cable signals and I’m generally pretty happy with the whole solution – as is my family.
For the last 2-3 months I’ve been noticing segfaults, abnormal process terminations and in some cases the complete MythTV stack terminates, leaving my wife without her regular Grey’s Anatomy or House, leaving me with a headache and a nagging suspicion that I need to fix the platform.
Any guesses on what’s going on?
Yep, faulty RAM. The backend is positioned in a warm and dry basement but to debug the system I have to disconnect the hardware and move the system into my home office where I have access to monitors, keyboards, benches and other tools.
I pulled the RAM, both sticks and tested each stick independently using Memtestx86. The first stick passes perfectly but the second stick fails within 5 seconds. Yep, that would do it. The problem is that I suspect I now have corrupt filesystems so I’m going to have to wade through some of the ext4 fsck support tools to validate/recover the system.
Luckily I have some spare disks so if push comes to shove and I have to extract the good recordings from the system onto spare disks before re-creating the filesystems, then that’s possible.
I like the fact that with ext4 I can delete 8GB recordings in a faction of a second, I don’t like the fact ext3 takes 20-30 seconds to perform the same transaction. Now I’m starting to wonder how reliable my long term recordings are, and how much faith I have in ext4 generally! I like to record a lot of shows to cover us over the summer ‘shortage’. I don’t go back an check these. If these shows are bad or marginally corrupt then I’ll be an unhappy camper.
Lessons learned? When your system starts segfaulting don’t wait a couple of months to deal with it, fix it else risk trashing your filesystems.
The only thing worse than playing ‘file system recovery’ is a wife constantly reminding you that she missed her weekly dose of ‘So you <blah> you can <whatever>’. On the other hand, it’s perhaps an ‘accidental’ way of dropping cruddy shows. đ
Troubles recording TVÂ = unhappy family.
I should go and get on with fixing it…. later.
Sorry for the trouble. I feel your pain.
I guess this is all related to the hvr-22xx zip files being gone?
Good luck.
Thanks for the ping Matt, they’ve been restored.
It’s never a good thing when is supposed to be nice and safely recorded…perhaps tucked away under a more compact encoding.
What’s even better when a minor blip in the signal(nothing on my end) causes a problem…but the hardware gets the blame.
On topic, I’ve had significant issues with grounding and sound. A ground loop and adding some level of grounding via a preamp helps, but I’m going to need to look at rearranging everything, as I think it’s causing some problems on my coaxial signal.
Instead of tuner driver and firmware problems, I’m betting that if I take the time to re-arrange and get the recording box away from n+1 misc. electronics, it’ll clear up.
Indeed. The system is back up now, hopefully in better shape. Now I just need to RMA the memory back to G.Skill. đ
@matt
Try to connect your Audio Video equipment to a Single known good Master Ground to avoid voltage current loops.
http://www.epanorama.net/documents/groundloop/
Steve –
What distro/release/kernel version are you running on this? I’ve got nearly the identical situation (though only using one HVR-2250, and one pcHDTV-2000) but I see recording lockups after running for a relatively long periods (days) They seem to be related to SPI errors accumulating and taking up all the message slots.