[CentOS] ext4?

Listee's...

I have a 5.5 box and I have formatted a partition as ext4 however I can't mount it, the mount command is telling me its an unknown file system type. fsck tells me the partition is a clean ext4 partition but I can't mount it.

Some reasearch has lead me to believe the problem is that ext4 isn't enabled in the kernel by default in 5.5 (this was originally a 5.2 box that has been upgraded over time, its now on 2.6.18).

I'm struggling to find some idiots steps to either get the kernel rebuilt or use the CentOSPlus repo's to get the ext4 module for the kernel etc....Can anyone point me at an idiots guide to make this work?