if there's a linux distro that has easy to set up, non-raid, redundant file storage, i'm all ears. i've tried amahi and it was a mess.
install any linux version
dd if=/dev/sda of=/dev/sdb bs=1M
Reboot to the 2nd drive
rename the parition IDs to be different from the other drive, since linux will be confused trying to mount partitions when you have two with the same UUID.
now you write a script that needs only three commands.
mount /dev/sdb1 /media/backup
rsync -a --delete <path to important files> /media/backup/<path>
umount /dev/sdb1
<optional> hdparm -y /dev/sdb <this spins down the backup drive after it's unmounted>
Now add that to the cron file to execute at whatever frequency you want. I do nightly at 5am.
Now you have a fully redundant system. If the primary drive fails, then you can boot the other drive and pretend nothing happened.
This is what I do for my file server, only I have a THIRD identical (and bootable) drive that is external. That one gets backed up every couple months, and I take it to work an lock it in a drawer. That's my "house burned down" backup copy.
I wasn't very familiar with linux when I set it up. Took me about 4-5 hours to figure it all out and get it all working perfect. So a little up-front work. But now that it's done, it's good to go for 4-5 years until I'm ready to replace the drives.
I suppose you may need to work on samba. I did that part about 8 years ago and carry the same samba.conf from computer to computer. It's not like linux ever changes drastically. That's the good part, even if it takes a few hours to learn what to do, once you learn it you're DONE. You can carry the important files forward to the next file server with little to no changes. You do the work once and it gets carried forward for DECADES.