I can mount an ext2fs filesystem from an 'old' Ubuntu without problem.
Code:
# fdisk wd0
Disk: wd0 geometry: 38913/255/63 [625142448 Sectors]
Offset: 0 Signature: 0xAA55
Starting Ending LBA Info:
#: id C H S - C H S [ start: size ]
-------------------------------------------------------------------------------
*0: A6 0 1 1 - 5098 254 63 [ 63: 81915372 ] OpenBSD
1: A6 5099 0 1 - 22945 254 63 [ 81915435: 286712055 ] OpenBSD
2: 82 22946 0 1 - 23011 254 63 [ 368627490: 1060290 ] Linux swap
3: 83 23012 0 1 - 38912 254 63 [ 369687780: 255449565 ] Linux files*
# disklabel wd0
# /dev/rwd0c:
type: ESDI
disk: ESDI/IDE disk
label: WDC WD3200AAKS-2
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 255
sectors/cylinder: 16065
cylinders: 38913
total sectors: 625142448
rpm: 3600
interleave: 1
boundstart: 0
boundend: 0
drivedata: 0
16 partitions:
# size offset fstype [fsize bsize cpg]
a: 81787372 63 4.2BSD 2048 16384 1 # /
b: 128000 81787435 swap
c: 625142448 0 unused
p: 255449565 369687780 ext2fs
A mount of the raw device fails:
Code:
# mount -t ext2fs -o ro /dev/rwd0p /mnt
mount_ext2fs: /dev/rwd0p on /mnt: Block device required
Using the 'normal' device succeeds:
Code:
# mount -t ext2fs -o ro /dev/wd0p /mnt
ls -l /mnt
total 256
drwxr-xr-x 2 root wheel 4096 Sep 24 08:38 bin
drwxr-xr-x 3 root wheel 4096 Oct 23 10:57 boot
lrwxrwxrwx 1 root wheel 11 Jun 22 2009 cdrom -> media/cdrom
drwxr-xr-x 4 root wheel 4096 Apr 20 2009 dev
drwxr-xr-x 134 root wheel 8192 Feb 13 05:31 etc
drwxr-xr-x 4 root wheel 4096 Aug 23 2009 home
lrwxrwxrwx 1 root wheel 33 Jun 21 2010 initrd.img -> boot/initrd.img-2.6.28-19-generic
lrwxrwxrwx 1 root wheel 33 Mar 4 2010 initrd.img.old -> boot/initrd.img-2.6.28-18-generic
drwxr-xr-x 19 root wheel 8192 Oct 23 10:57 lib
drwxr-xr-x 2 root wheel 49152 Jun 22 2009 lost+found
drwxr-xr-x 4 root wheel 4096 Feb 13 03:00 media
drwxr-xr-x 2 root wheel 4096 Apr 13 2009 mnt
drwxr-xr-x 2 root wheel 4096 Apr 20 2009 opt
drwxr-xr-x 2 root wheel 4096 Apr 13 2009 proc
drwx------ 10 root wheel 4096 May 18 2010 root
drwxr-xr-x 2 root wheel 4096 Oct 23 10:57 sbin
drwxr-xr-x 2 root wheel 4096 Mar 6 2009 selinux
drwxr-xr-x 2 root wheel 4096 Apr 20 2009 srv
drwxr-xr-x 2 root wheel 4096 Mar 31 2009 sys
drwxrwxrwt 11 root wheel 4096 Feb 13 05:31 tmp
drwxr-xr-x 12 root wheel 4096 May 18 2010 usr
drwxr-xr-x 16 root wheel 4096 May 18 2010 var
lrwxrwxrwx 1 root wheel 30 Jun 21 2010 vmlinuz -> boot/vmlinuz-2.6.28-19-generic
lrwxrwxrwx 1 root wheel 30 Mar 4 2010 vmlinuz.old -> boot/vmlinuz-2.6.28-18-generic
Are you sure you are using ext2fs or ext3fs?
ext3fs is compatible with ext2fs, but I am not sure ext4fs is