From Ext3 to Ext4 don't work ?

[pacmo]

Linux Debian Lenny guest ext3
I migrate it on ext4 so :
1) sudo tune2fs -O extent,uninit_bg,dir_index /dev/sda1 .. sda2 sda3
2) fsck -pf /dev/sda1 .. etc
3) Modify grub add : rootfstype=ext4
4) Modify /etc/fstab ext3 in ext4
5) Riavvio e si blocca a grub>
When it start, it stop so :
grub>
I have tried
root (hd0,0)
kernel /boot/vmlinuz-2.6.26-2-686 root=/dev/hda1 ro quiet rootfstype=ext4
initrd /boot/initrd.img-2.6.26.....

This is the result :
Begin:Waiting for root file system ...
Warning bootdevice may be renamed. Try root=/dev/hda1
Gave up waiting for root device Common problems :
- Boot args (cat /proc/cmdline)
-Check rootdelay = (did the system wait long enough ?)
-Check root =( did teh system wait for the right device ?)
- missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/hda1 doesn't exist Dropping to a shell
Can you help me or ext4 don't work in VBox ?
Thank's

[Sasquatch]

This is not a VB problem, you messed up the file system on the Guest. Something you would end up doing on a native system too. Please go to the Debian forums (or Linuxquestions) and try to solve this with their help. This is off-topic on this forum.

Even the howto on the Debian wiki states this:

Do a backup before attempting this procedure. It may render your system unbootable, and may destroy your data.

Taken from http://www.debian-administration.org/ar ... filesystem