[SunHELP] Linux filesystem question

[James]

OK, I apologize in advance for a Linux question here, but this crew is the 
most knowledgeable I know.

I was trying to find some files that I knew existed yesterday, but they 
were missing this morning. The directories were there, but not a file to be 
found in the whole tree. The fs is "/".

I tried a fsck and got a screenfull of sda1 write errors. I tried a 
shutdown and got same. Rebooted. Lilo/kernel runs through the boot until it 
tries to mount the root filesystem. It does manage to load the ext3 module, 
finds the disks, mounts /proc.

Fails with this:

creating root device
mounting root device
mounting root filesystem
VFS: Cant find ext3 filesystem on dev sd(8,17)
mount: error 22 mounting ext3
pivotroot: pivot_root(/sysroot,/sysroot/initrd) failed: 2
Freeing unused kernel memory: 304k freed
Kernel panic: no init found. Try passing init= option to kernel.

Questions:
Might this disk and its data recoverable?

If not, is there a chance that if I replace it I can mount is as another 
device (sdcX) and recover data.

Last resort question, If I install a new disk and reload linux (redhat 7.3) 
can I prevent itfrom overwriting sdbX (the second disk) and avoid even more 
catastrophic lossage?

Lesson learned....
Normally I wouldn't have a big / (the whole freaking sda) and store files 
there, but the braindead installer chose this and I didn't object. Next 
time I'll choose a saner fs layout.