Re: [SLUG] Copying and booting linux with a partition with a different filesystem type

From: Eben King (
Date: Sun Mar 30 2008 - 21:55:34 EST

On Sun, 30 Mar 2008, Donald E Haselwood wrote:

> Can linux, e.g. Suse 10.3, copied and booted up on a partition with a
> different filesystem from the one it was installed on? My experiments
> suggest that this cannot be done, but maybe there is something I'm
> overlooking.

I'd have to say "yes, probably", because at one time I had ext2 on / and now
I have ext3. Odds are I didn't reinstall to do this as I rarely install.

> For example, I have Suse 10.3 installed on a partition with ext3. I copy the
> whole system to a partition formatted with ext2. I fix fstab and grub. Boot
> fails early, ending with "Loading ext3"; "Mount: unknown filesystem type
> ext2"; then," kernel panic...". If I do the same copy/fix-up process to a
> partition with ext3 it works fine.

I've always used lilo (well, grub is on the laptop but I haven't had to futz
with it). Maybe your grub doesn't have a handler for ext2?

> I also tried it on a machine with Suse 10.2 installed on an ext2 partition
> and copied to an ext3 partition. Boot fails with "unknown filesystem type
> ext3" when the filesystem type on the copy is ext3; of course in this case
> the filesystem types are reversed, i.e. "Loading ext2"; "Mount: unknown
> filesystem type ext3." And again, it works fine if the partition
> filesystem type for the copy is the same as the installed type, ext2.

Can you tell what's giving you the "unknown filesystem" message? If it's
the kernel, you need to make sure the module for ext3 is in the initrd or
compiled into the kernel.

> This suggests that something in the kernel/initrd images has the filesystem
> type expected and fails when a different one is encountered. So far, I
> haven't been able to turn up anything to confirm/refute this on the web.

See if there's some way to reconfigure grub. Maybe there's a process where
you choose among the valid filesystems for /

-eben   QebWenE01R@vTerYizUonI.nOetP
         Two atoms are walking along.  Suddenly, one
       stops.  The other says, "What's wrong?" "I've lost
         an electron." "Are you sure?" "I'm positive!"
This list is provided as an unmoderated internet service by Networked
Knowledge Systems (NKS).  Views and opinions expressed in messages
posted are those of the author and do not necessarily reflect the
official policy or position of NKS or any of its employees.

This archive was generated by hypermail 2.1.3 : Fri Aug 01 2014 - 15:30:55 EDT