Could some Linux guru please kindly help ? I am trying to debug the issue of a desktop that has for the last two weeks started having kernel panics at boot time. This machine has been running flawlessly for the last 8 years, and has had three OS upgrades. I am using memtest to try to understand the issue.
The following is part of the memtest output:
Reading all physical volumes
Buffer I/O error device hdc logical block 0
......
......
Buffer I/O error device hdc logical block 15
Illegal node for this track or incompatible media (asc=0x64 ascq=0x00)
The failed "Read 10" packet command was /dev/hdc: read failed after 0 of 4096 at 0 Input/output error
and similar set of mesaages

After this udev checks correctly, and hardware, storage and audio are initialized

However sometime in the middle of the boot process, a kernel panic occurs with message
Kernel panic -- not symcing : Fatal exception in interrupt

I am somewhat confused about your problem. Memtest is a program to test the memory (RAM) of your machine, it doesn't test the other hardware. But the error outputs you get are pointing to a failure with your harddisk or CD/DVD-drive (don't know what is /dev/hdc in your machine). So I would recommend the following:

If the device /dev/hdc is a harddisk, backup your important data on that disk, download and burn the manufacturers diagnosis tool and test the disk.

If the device /dev/hdc is a CD/DVD-drive remove the media from it and try again. If that doesn't help unplug the device and try again.

That looks more like a HDD issue rather than memory issue. Perhaps you should run a badblocks check on /dev/hdc to verify...

Doesn't make sense either. Hdc ought to be the third hard drive in the original mounting way.

Could that mean the cd-rom is failing and you can't get memtest to start?

That might point to a drive controller failing but at this point anything could be failing.

Thanks to each of you for your helpful suggestions. I checked the boot order in the BIOS, and the first two were Harddisk. Then I unplugged the power connection on the CDROM, and right now the machine is up with no kernel panics. Looks like a CDROM reader/writer related problem.