I'm looking at building a new home server and would like a flexible filesystem. Both btrfs and zfs are interesting. I want to be able to do soft raid and have flexible solution allowing me to expand storage easily as I add hard drives. Not interested in hardware raid due to cost. Since this is a non-essential server, I'm willing to play around and take some risks. This media server will be available over the Internet for remote playback. Most likely will run Plex Media Server software. I'm thinking of running Ubuntu 12.04 since some of the software I want to use seems only supported on the LTS.
Appreciate any advice.
Edit: changed title to include LVM + md software raid.