So today I updated the kernel on my desktop to 2.6.28 and with the update comes the stable EXT4. So I thought what the hell, it should be simple to do this migration from ext3 to ext4. It relatively was.
First I converted my /home and / filesystems to ext4. Then I had to boot into the arch live cd, update it, and fsck my partitions. There were a lot of errors that it found.. Anyways, I did that then I tried booting… what do I get? Cannot mount root partition —- KERNEL PANIC!!! So i tried to mount it from the live cd but the kernel on there didnt support ext4 so couldnt do that.. then I tried booting into the fallback kernel, and that worked! So after some messing around, I rebuilt the kernel and that seemed to do the trick. All works and I’m running EXT4. But I’m still waiting to try BTRFS.. Maybe there will be a dev version in 2.6.29.