Richard Jones' Log: Some Linux "fun"

I got a new disk drive from a friend and plugged in last night.

Of course it wasn't easy...

When I booted it up, I got the strangest thing. "Waiting for root file system" which then times out. I don't know if you've ever been thrown into the "ash"/"busybox" minimalist environment that you get when boot fails, but it's not fun ;) I had to try to figure out what was going on ...

It turns out that Linux was trying to mount my root filesystem (sda3) from the new disk - which didn't actually have a partition "sda3". Even though I plugged it in as drive #3 on the motherboard, and the BIOS detected it as drive #3, Linux ordered it as drive "sda" because (presumably) it's an SATA-1 drive and the existing two drives (which used to be sda and sdb) are SATA-2 drives. "1" sorts lower than "2" I guess :)

I eventually figured out that the drives had been re-ordered, and then figured out which files to edit to make it all work again (though there was some guesswork when editing the grub menu.lst). My RAID-1 array was broken as well since it used to refer to sda4 and sdb4 and now it couldn't find sda4 but could find sdc4. I ended up with two RAID disks mounting sdb4 and sdc4 independently. Fortunately I could just delete one and add its disk back to the other array, wait for the rebuild, and all's well again.