[lug] tracking down DVD drive problems

[Michael J. Hammel]

Here's one for the hardware gurus.  I've got two DVD-R drives that
appear to be causing errors:

Feb 10 17:08:30 feynman kernel: Buffer I/O error on device sr0, logical
block 102703
Feb 10 17:08:31 feynman kernel: sr 1:0:0:0: [sr0] Result:
hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
Feb 10 17:08:31 feynman kernel: sr 1:0:0:0: [sr0] Sense Key : Medium
Error [current]
Feb 10 17:08:31 feynman kernel: sr 1:0:0:0: [sr0] Add. Sense: CIRC
unrecovered error
Feb 10 17:08:31 feynman kernel: end_request: I/O error, dev sr0, sector
410808

I've tried both drives on two different systems.  One worked okay on the
first system for awhile, then started giving these errors.  Both worked
okay on the second system at first, then started giving these errors.
Both systems run the same kernel (2.6.23.14-64.fc7) and same distro
(F7). I'm curious:  isn't this a 64 bit kernel?  I don't think the first
of these systems is a 64 bit CPU though it appears the second one may
be, and I know I wasn't running a 64-bit kernel on either system before
the most recent yum update (are there any known issues with this
kernel?):

System 1:
mjhammel(tty1)$ cat /proc/cpuinfo
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 6
model           : 8
model name      : AMD Athlon(tm) XP 1800+
stepping        : 1
cpu MHz         : 1500.165
cache size      : 256 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca
cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow up ts
bogomips        : 3002.14
clflush size    : 32

System 2:
mjhammel(tty0)$ cat /proc/cpuinfo
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 47
model name      : AMD Athlon(tm) 64 Processor 3000+
stepping        : 2
cpu MHz         : 1000.000
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca
cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext fxsr_opt lm
3dnowext 3dnow up pni lahf_lm ts fid vid ttp tm stc
bogomips        : 2010.48
clflush size    : 64

Both systems IDE hard disks are working fine on the primary controller.
Both DVD drives are being used to rip my collection of DVDs for use with
MythTV.  Both DVD drives are pretty much cheapest-available at the time
of purchase.  My DVD drive in my laptop seems to work fine with the same
DVD disks.

I thought at first it was the IDE controller (Secondary controller on
both systems) but it seems unlikely that IDE controllers on both boxes
might have died at the same time.  Then again, one of the DVD drives is
brand new.  It seems unlikely that both drives are dying now too.

I've done a bunch of trial and error tests and I'm not getting convinced
one way or the other that the drives or the controllers are dying.  So
I'm looking for suggestions on how to figure out what is working and
what isn't with the fewest number of "crack the boxes open and move
things around" options.  What is a good (cheap) way to test the IDE
controllers in both boxes?  And how can I verify that the DVD drives are
working or not?

I'm about to reboot into the previous kernel (2.6.23.1-21.fc7) to see if
that helps, mostly cuz I haven't tried this yet and it doesn't require
cracking the box open yet again.