Thanks as ...... that brings me back to Busybox? or is it ash? support for ext4 ...... I dunno for sure what is being used at that time ...
it is really busybox, /initrd/bin/ash is an hard link to /initrd/bin/busybox, the ext4 support should be provided from kernel, but as I understand,
being a module it's actually not loaded until rootfs is mounted, and rootfs is not mounted because the mount statement actually fail.
ext3 doesn't fail because because can be mounted as ext2.
if you format a partition as ext3
, and then you try to mount it as ext2 (mount /dev/sdaX /mnt -t ext2) will succed
if you format a partition as ext4
, and then you try to mount it as ext2 (mount /dev/sdaX /mnt -t ext2) will fail