ext4 migration on my laptop

ext4 migration on my laptop

1:05 AM PST, December 30, 2008, updated at 1:07 AM PST, January 16, 2009

I migrated from ext3 -> ext4 on my laptop.

tune2fs -O extents,uninit_bg,dir_index /dev/sda1
After running this command you must run fsck.

On kernels < 2.6.28 one needs:
tune2fs -E test_fs /dev/sda1

I thought of no bad and simply rebooted. That was a mistake: grub won't boot from an ext4 partition. So I had to install grub2 instead.

grub2 on the other hand would boot, but the initrd needed to be rebuilt: I had to add the ext4, jbd2, and crc16 modules.

After that the laptop would boot, but the system tries to mount the root as ext3, which fails due to "optional unsupported features (40)". I had to pass an additional parameter:

rootfstype=ext4

in grub.

On kernels < 2.6.28 one needs to use ext4dev instead of ext4