I currently have a personal nas running ubuntu server, but I’m considering moving it to opensuse leap. I’ve dabbled a bit with leap inside of virtual machines, but maybe someone more experienced with it can give me a more complete opinion. Also, is btrfs worth getting into, or can I just use ext4 and loose out on nothing (except snapshots)?
That’s correct. Btrfs will simply divide your disks in 1GB chunks, and when writing, always ensure that a bit of data is always stored in 2 chunks on two different disks. You can also do 1C3 or 1C4 if your data is truly that critical, which means data is always stored in 3 or 4 chunks (on different disks), respectively. Of course, that also requires at least they amount of drives.
This chunking is also the reason why the sizes of the drives don’t have to match, as long as it’s possible to divide it evenly you won’t lose space as unused. Simply put, make sure your largest drive is not larger than your other drives combined and you should be fine.
In my case, data will always see one copy on the 4gb drive, and another on either of the 2gb drives.