Yesterday morning, in preparation for a change to the database version on our main machine (running SLES 11.1 - SuSE Enterprise Server), our on-call hardware guy had my boss apply a number of updates to the machine. According to her, after applying the patches, the machine said it needed to reboot, so she allowed it to do so, but it never came back up.
Powering the machine down, then back up permits it to come up manually, but it won't (of itself) go past the GRUB boot loader screen - clicking on either the regular or the failsafe options goes to a blank screen that remains until the machine is rebooted. Dropping into the Grub console gets a little further, but attempting to boot from there with the instructions I found online for that gives a message 'probing edd', then appears to freeze at that point as well.
An attempt to get into the machine with a Knoppix live cd (the one in the Linux for Dummies book) permitted Knoppix to come up, but I can't figure out how to mount the system's partition (/dev/sda2) from there - attempting a read-only mount command with that path tells me that '/dev/sda2 is not a valid block device'.
After getting a downloaded copy of an installation disk (apparently for SLES 11.2 instead of 11.1 - we got the download from our hardware guy), I was able to get in and, following more instructions found online managed to get to the Expert Tools screen in the Repair options. There, Boot From Disk told me there were no bootable partitions on the machine, the file system check told me that /dev/sda2 was ok, and I was informed that there were no Lost Partitions found. I have not tried anything else from that screen.
Attempting to reboot the install disk and run the automatic repair brought up a notice that the Initrd appears to be damaged somehow, (missing module mbcache) but the repair attempt could not be made - 'calling mkinitrd failed'. The bottom segment of that log included the following:
Kernel image: /boot/vmlinuz-188.8.131.52-0.7-pae
initrd image: /boot/initrd-184.108.40.206-0.7-pae
node name not found
Root device (/dev/sda2) not found
There was an error generating the initrd(1)
After that, I was informed that there was an error in the boot loader, and selected Repair, which brought me up to a screen with Boot Loader settings. That's where the machine is currently sitting, as I have no clue how to interpret those.
If anyone has any suggestions as to how I should proceed from here, or possibly any advice on how to get the Knoppix live cd to mount the system's hard drive so I can at least attempt to tar up and carry away our data, I would be very grateful to hear them.