11h.net

Like we need another MythTV-Related post. I guess its now so important to Eric & I we have to blog on it though!

Anyway, I’ve had my MythTV system up and running pretty nearly flawlessly for almost 2 months (which works out to 288 recordings in 259 hours and 14 minutes taking up 263 GB of disk space). My system specs are:

Backend

• Old AMD Athlon 1.666GHz
• 256MB Ram
• Slackware Linux 10.2
• 300GB SATA Hard Drive (to be upgraded to RAID soon)
• PVR-150MCE PCI Capture Card
• DirecTV Hughes Receiver connected via SVideo
• IR Blaster bundled with the PVR-150 to change channels
• MythTV SVN r9070 (Backend & MythWeb)

Living Room Frontend

• Used Softmodded X-Box running Xebian
• Microsoft DVD Remote Control
• MythTV SVN r9070 (Frontend with MythVideo, MythDVD, MythRecepie plugins)

The X-Box is a little slow in the user-interface, but otherwise seems to work flawlessly. It plays back SD MPEG2 and MPEG4 videos without any problems.

For my second Frontend, which is currently in the bedroom, I used the following System:

2nd Frontend

• Old HP Pavilian Motherboard acquired quite some time ago from Tyson
• 1GHz Intel Celeron
• 128MB RAM
• 10GB Hard Drive
• nVidia GeFORCE4 MX4000 64MB PCI With SVIDEO Out
• Cheap 10MBit PCI Network card I had laying around
• Slackware 10.2 and same version of MythTV

Got everything up and running quite easily! Here’s a quick list of “problems” I had for documentation (or laughing) purposes:

• Remembered that this POS doesn’t have an AGP Slot — I was going to use this for a frontend instead of buying an xbox when I remembered that this motherboard doesn’t have an AGP slot … that means I’d have to buy a new PCI video card… which I finally did.
• Power Supply Connector — Since I had used this power supply for several things except a computer, the green “Power-On” pin in the connector had become too large from sticking too many paper clips in it. Everytime I’d, say, open the CDROM drive to insert the Slackware boot disc, the drive would vibrate against the power supply, which would move the cable just enough to power off the system. Fixed by crimping it back to a tighter fit.
• Bad Hard drive — My 60GB Hard Drive I was planning on using won’t read past about 57% of the disk (where it died trying to format it). Ugh. Ended up using an older 10GB drive I had laying in the garage.
• Noise on TV Screen — Once everything was working and I moved it to the bedroom and hooked it up to the TV screen, I realized there was some “digital” noise interfering with the video! Its pretty faint and unnoticable when watching TV, but its very noticable during bootup on the black console screen.
• NO FREAKING AUDIO OUT CONNECTOR — I think i’m starting to realize why Tyson wanted to get rid of this stupid computer … the motherboard doesn’t have an audio output jack. Only three pins on the motherboard. …Time to go manufacture my own RCA cables…
• Loud volume — With the mixer set up to full volume, the audio got all distorted. Whats worse (and funny)? The audio was interfering with the video on my TV. I got little rippiling horizontal lines on the video. Whats worse yet? When I pressed “mute” on the TV (since it was loud an annoying), I could still hear the audio! I must have been overloading the TV’s audio circuits. I’m sure eric can explain better…

Once I “fixed” everything, its great! Now to try and get a remote control working for it…

After trying to troubleshoot some MythTV and system issues this afternoon, I managed to loose my storage raid array. It was really quite stupid. I forgot that you don’t need to make a partition for an md0 device…

For those of you needing further clarification, once a raid array (md device) is created, there is no need to make a partition on it. It _is_ the partition!

When mkfs.jfs /dev/md0 was used, it corrected the ‘partition’ that I created.

So, I destroyed the data on /dev/md0 by creating a partition and then formatting it. No big deal, it’s just TV. Oh wait. The new series of the Simpson’s and Doctor Who were in there. Plus three episodes of the best Saturday night comedy show Almost Live!

Doctor Who is the only one that I’m worried about. The guide data shows that the first two episodes won’t be airing for the next three weeks!

After all my troubles this afternoon, what else could go wrong? Well, this evening while trying to troubleshoot why I can no longer fast forward or rewind while watching live TV or recorded shows, I zeroed out the first megabyte of the raid array trying to determine the SCSI raid array performance.

Knowing that I just toasted the partition table and anything else that might have been important, I tried to copy off the shows that I was able to record from this afternoon - after destroying the raid array the _first_ time. Well, almost on queue, MythTV locked up the system while I was in the middle of copying the data from the raid array. Damn it! Throw me a fricken bone here!

What I did was:

dd ‹ /dev/zero › /dev/md0 bs=1k count=1024

What I thought I was doing and meant to do was:

dd ‹ /dev/zero › /mnt/store bs=1k count=1048576

This would create a 1GB file with zero’s in it. Basically, a quick way to calculate disk transfer speed. I thought that the reason I couldn’t FF or REW was because of slow disk performance. Well, with 119 MB per second transfer, it wasn’t the disks.

In the process of killing the raid array - twice, hard resetting, soft resetting, and replacing hardware, my MythTV databases got mangled and because of this I could not watch live TV or watch saved recordings. However, recordings that were underway, we’re still recording just fine, mythbackend couldn’t insert the information about the recording into the mythconverge database.

Here’s what the mythtv was reporting when the database was corrupt:

2006-04-02 22:04:44.554 DB Error (delta position map insert):

Query was:

INSERT INTO recordedmarkup (chanid, starttime, mark, type, offset) VALUES ( ‘105

4′ , ‘2006-04-02T22:04:43′ , ‘1′ , 6 , ‘0′ );

Driver error was [2/1016]:

QMYSQL3: Unable to execute query

To fix the problem I had to use these commands to repair the tables in the database:

myisamchk -r /var/lib/mysql/mythconverg/recordedmarkup.MYI

I tried myisamchk /var/lib/mysql/mythconverg/recorded.MYI which also had errors…

So I figured it wouldn’t hurt to just:
myisamchk -r /var/lib/mysql/mythconverg/*.MYI

Seemed to fix a lot of problems – including my original problem of FF and REV!!!