[BLUG] RAID-like redundancy for a linux?

I have a home server (sporting a dual core AMD E-350 and 4 gigs of
ram) running Ubuntu Server 12.04 and have been really happy with it
for the last 6 months. The one area where I am not happy is my lack
of data redundancy. I use this as my NAS as well, using offsite
backup for my personal and irreplaceable files (I use SpiderOak) but
it would still be nice to have some redundancy locally in case of a
single drive failure. I'm wondering if anyone could recommend any
software solutions to doing some sort of RAID-like redundancy within
Ubuntu server? I've been reading about ZFS, which seems interesting,
but I also see that it cannot be included in Linux because it is
incompatible with the GPL. Is ZFS worth considering? Are there other
solutions like ZFS out there that I can use? That is, is there some
software solution that allows creating a pool of disks that will take
care of data redundancy and be able to recover from a drive failure?
Also, does using different capacity disks make this a much harder
challenge?

Thanks!

Ben
_______________________________________________
BLUG mailing list
BLUG@linuxfan.com
http://mailman.cs.indiana.edu/mailman/listinfo/blug