Comment 19 for bug 316872

Added this text:

Ext4 support in GRUB was provided by Colin King. If you choose to upgrade your `/` or `/boot` filesystem in place from ext2 or ext3 to ext4 (as documented on the [[http://ext4.wiki.kernel.org/index.php/Ext4_Howto#Converting_an_ext3_filesystem_to_ext4|ext4 wiki]]), then you ''must'' also use the `grub-install` command after upgrading to Ubuntu 9.04 Beta to reinstall your boot loader. If you do not do this, then the version of GRUB installed in your boot sector will not be able to read the kernel from the ext4 filesystem and your system will fail to boot.