Re: 2.4.20-rc1 dirty ext2 mount error

[Matt Bernstein]

At 17:26 +1100 Keith Owens wrote:

>>> The root partition was originally ext3.  fstab now contains
>>> 
>>> /dev/sda1               /                       ext2    defaults        1 1
>>> 
>>> Booting 2.4.20-rc1 (ext3 as a module, not loaded yet) with a dirty / gets
>>> 
>>> EXT2-fs: sd(8,1): couldn't mount because of unsupported optional features (4).
>>> Drop back to 2.4.18 and it works, automatically running fsck.ext2 -a /dev/sda1.

>Come up on 2.4.18-14 from RH.  It detects ext3 and cleans the journal,
>even though fstab says ext2.  Then ext2 does fsck.ext2 -a /dev/sda1.  I
>guess the question is why ext3 is being used when fstab says ext2?

My guess answer is that /etc/fstab lives on / and can't be read till it's 
mounted. 2.4.18-14 has the ext3 modules loaded from initrd so the kernel 
can have 2 guesses at how to mount /

>Especially when that stuffs up booting into other kernels that do not
>have ext3 support at all.

Maybe you need to tune2fs -O ^has_journal /dev/sda1, or build an initrd 
which doesn't load the ext3 modules.

Matt