how to force ext2 root fs type at boot?

["Robin Sinclair" <sin02 globalnet co uk>]

Hi guys'n'girls,

I think my question is :
How can I tell a redhat 2.4.x  kernel (via grub or LILO command-line
parameters) that the root filesystem is ext2 and not ext3 ?
I thought it would just look in /etc/fstab, but presumably it needs to know
what fstype the  root is before mounting it; the words 'chicken' and egg'
spring to mind.

Or does some initrd jggerypokery go on?

My problem is the following:
After upgrading from RH 7.2 (kernel 2.4.7-10 with ext3 root fs  ) to a
vanilla (non-RH) 2.4.10 kernel (no ext3 support), the system wouldn't boot
since the new kernel had no ext3 support.

I had to do a 'tune2fs -O ^has_journal ' and edit fstab , in order to get it
to boot.
(is this enough to convert back to ext2 ?)

Unfortunately before making a new boot floopy at this stage, I must have
made an error in my grub.conf, and so now I can't boot from grub.
my old boot floopy fails to boot : it loads the ext3 and journaling modules
, then the kernel panics since it can't mount the root fs, mentioning that
the root fs has no journal.

I am/was using the standard RH 2.4.7-10  initrd.img.

Any ideas or tips on what I did wrong anyone?
many thanks
Robin

PS Incidentally, grub shows the 'loading 2nd stage loader' and then reboots
the PC. grub was working fine before I added a 4th kernel to grub.conf and I
omitted to add an initrd line, I'm not sure if that's what caused it to stop
working (I'm new to grub)