I'm installing 3x2TB HDDs into my desktop pc. The drives are like-new.
Basically they will replace an ancient 2tb drive that is failing. The primary purpose will basically be data storage, media, torrents, and some games installed. Losing the drives to failure would not be catastrophic, just annoying.
So now I'm faced with how to set up these drives. I think I'd like to do a RAID to present the drives as one big volume. Here are my thoughts, and hopefully someone can help me make the right choice:
- RAID0: Would have been fine with the risk with 2 drives, but 3 drives seems like it's tempting fate. But it might be fine, anyhow.
- RAID1: Lose half the capacity, but pretty braindead setup. Left wondering why pick this over RAID10?
- RAID10: Lose half the capacity... left wondering why pick this over RAID1?
- RAID5: Write hole problem in event of sudden shutoff, but I'm not running a data center that needs high reliability. I should probably buy a UPS to mitigate power outages, anyway. Would the parity calculation and all that stuff make this option slow?
I've also rejected considering things like ZFS or mdadm, because I don't want to complicate my setup. Straight btrfs is straightforward.
I found this page where the person basically analyzed the performance of different RAID levels, but not with BTRFS. https://larryjordan.com/articles/real-world-speed-tests-for-different-hdd-raid-levels/ (PDF link with harder numbers in the post). So I'm not even sure if his analysis is at all helpful to me.
If anyone has thoughts on what RAID level is appropriate given my use-case, I'd love to hear it! Particularly if anyone knows about RAID1 vs RAID10 on btrfs.
It combines capacity without any fancy striping. It can still provide some performance benefit as different blocks of the same file can be stored on different drives, but it doesn't stripe data across the drives for performance.
It also allows you to just add more drives later. The drives don't need to be the same size or type. You can also remove drives, provided there is enough free space to move the data on a drive to the ones that will remain.
It really just pools the storage capacity into one big volume.
If a drive fails, it still takes the whole volume with it tho. But as long as you monitor smart, it is fairly simple to try ejecting a failing drive from the device group before it takes the whole thing with it.