I have a RAID array, that I want to be able to swap between my router and my NSLU2. The NSLU2 uses an ARM processor, so the maximum size of ext2/ext3 filesystem is just 2TiB. Using ext4 would allow me to format the full 6TB array as a single partition, and be accessible on the NSLU2.
Compiling ext4 into the kernel seems pretty easy. But it occurred to me before doing this I should check if the tools would also need updating for this to work?