kernel panic/bad drive/update incomplete

[sevendogzero]

Got a few things that all add up to a mail server that no longer boots.

Story
1. Noticed my email server wasn't responding
2. Logged onto the server (it still booted up) and ran "yum update"
-Update locked up during a Java update
3.Got Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)...
swapper not tainted 2.6.32-754.18.2.e16.x86_64 #1

My hunch is one or both of the 500gb the hard drives is on it's way out.

Hoping someone can give me a couple steps to try to get it booting again
Maybe rebuild the grub...or use a rescue disk somehow, then get the mail data moved to a new server.

Haven't spent much time with disk boot/recovery chores, mostly a programmer, so more detail the better.

Sometimes the boot menu shows up, sometimes not. Just tried booting off the second kernel...blinking cursor...nothing
What a way to spend Labor Day

Regards,
Bret

[TrevorH]

If your disk is failing then it's failing and there's not much you can do about that. Though

3.Got Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)...

Might well be the result of a previous yum failure as it generates the initramfs for the newly installed kernel in the cleanup phase not during install of the package itself. But if it does the same thing on a previously working kernel then the disk is most likely toast.

See if you can boot anything at all and then run smartctl -a against the drive(s) and see what the result is.