Binary package hint: base-installer
Using Edgy to build a couple servers, amd64 and i386... found that I had to fool around in a shell to adjust the chunksize of the RAID 5 arrays I built on these servers, and also found that mdadm is being called without the --assume-clean flag when telling the installer to create new file systems on the array, which does not bypass array reconstruction (which is very annoying). The last bit is problematic because when it tells you to reboot and you do it, the arrays will start reconstruction all over again after reboot, slowing down the whole install process.
It would be extremely helpful to be prompted for chunksize, with a blurb of course that says if you don't know what this is for, just use the default (64). I have big arrays that work much better (30-40% faster) with 256 chunksize and would have preferred not having to shell out and umount/mount stuff and continue.
I also don't know if the "-R stride=X" parameter is being passed to mke2fs either, but that also needs to be adjusted based on the chunksize.