Kernal panic after installing more memory, won't boot
 

Dell Dimension 2300
Fedora 8 recently installed
Single boot system

I added another 256 memory module to the existing 256 MB

The memory checked OK during the initial boot-up phase

But Fedora failed to boot.

There were a lot of numbers and then

Unknown Boot option
Kernel panic - not synching: Attempted to kill the idle task!

How can I get the system to start with the upgraded memory? After pulling the new memory module out, Fedora started normally.

I sure hope I don't have to reinstall Fedora just because I added some memory.

There is a high probability that the new ram stick is bad. Boot off of any live cd that has memtest. I use System Rescue CD, but I think the Fedora install cd might have it on there. Check the F1-4 menu's when you boot off the cd and look for a memtest boot parameter.

Run memtest on each ram stick individually. I'd put money on you getting errors immediately after the test starts on the new stick.

For the record, what are your boot options? This is easy to see in an interactive GRUB session. Just highlight the selection you normally use (with arrow keys) and press the “e” key. There will be a line that says “kernel foo options” (where foo is the path to the kernel). If you don’t have an interactive GRUB, you’ll need some way of reading your grub.conf (perhaps a livecd).

An alternative method for determining the boot options is by reading the contents of /proc/cmdline. Obviously, you’ll need to be able to boot linux for this to work (so remove the likely-faulty ram before you try).

There's a line that just starts with 'Kernel', but doesn't say 'options'.

Here's what the line says:
Kernel /vmlinuz-2.6.23.1-49.fc8 ro root=/dev/VolGroup00/LogVol00 rhgb init /initrd-2.6.23.1-49.fc8.img

Note: after rhgb there is a small arrow ->, which I assume means that the line carries over to the next line. In other words there are two lines visible, which I have typed out as one line.

proc/cmdline is completely empty. A blank file. (opened in Kate)

I opened grub.conf as root in Kate and that appears to be a blank file too. No visible text.

Looks like you were right. memtest found errors right away.

Thanks for the help.