[ILUG] Odd Ubuntu hoary boot time error

[Niall O Broin]

When I boot an Ubuntu hoary box which has a jfs root filesystem, I 
encounter a couple of errors at boot time which seem benign, but are 
nonetheless puzzling. Extract from dmesg:

Restarting tasks... done
VFS: Can't find ext3 filesystem on dev sda2.
VFS: Can't find an ext2 filesystem on dev sda2.
Adding 971924k swap on /dev/sda4.  Priority:-1 extents:1


Not finding an ext[23] filesystem on sda2 isn't at all surprising, 
because there isn't one there - it's the root filesystem, and is JFS. 
But why on earth is an ext[23] filesystem even being looked for?

So, a little spelunking and I came across this in /sbin/init on the 
initrd:

rootfstype=*)
        fstype=${i#rootfstype=}
        ;;
esac
done
if [ -n "$fstype" ]; then
        mount -n${ro}t "$fstype" ${flags:+-o "$flags"} $device /mnt

That and a little googling (very little info. there) led me to try 
adding

rootfstype=jfs

to the grub kernel line. That then made me very glad I was using grub 
rather than lilo as it failed to boot at all - claimed it couldn't find 
a root filesystem. A quick edit of the command line in the grub shell, 
and I was sorted (not forgetting to edit menu.lst when the box booted 
:-) )


As I said, the error is relatively benign, but I'd not mind getting rid 
of it.


Niall