I’ve always wondered, given the warnings in documentation, if there are any people brave enough to try Btrfs in a RAID5/6 configuration. Has anyone here actually tried it with “real” data?
it’s still unstable and shouldn’t be used for anything except testing
If the devs say “unstable”, it’s probably unstable.
Given how flexible RAID1 in btrfs is, I don’t really see any benefit in using RAID5/6.
If the people on Phoronix are to be believed, it’s a buggy mess that will eat your data. Either way I would recommend using LVMRAID (as it’s much more mature) and putting BTRFS on top. Then you can put DM-Crypt between them and get easy FDE.
Some people in the comments of this claims to use it with real data https://www.phoronix.com/news/Linux-6.2-Btrfs-EXT4
If you use it don’t forget to use RAID1 for metadata
Yes.
I’d like to hear more. Are you still using it? What’s kind of data do/did you store on it?
Yes, as in, there were people using Btrfs RAID 5/6. It didn’t end well. Not that I’ve used it - I very much prefer having my data safe.
The warnings in the docs are there for a reason - those modes of Btrfs simply aren’t finished and thus aren’t fit to be used.
You can test this yourself easily in a VM, this will let you see how things fail for Btrfs 5/6 when one of the disks “fails”.
There are some folks over on aliensite that have been using RAID-5 and -6 for a while. Personally I’ve never tried it, because my use case needs the data redundancy more than the disk space.
As far as I know, as long as you’re not worried about either your data or a sudden power failure, they’re pretty solid. It’s a sudden system outage that is the danger.
Fragile. Works great when its working. When thjngs go wrong it’s difficult to see how anything can be salvaged.
I use it on my laptop and haven’t had any issues
It depends on what you call “real” data.
I find it good enough for home NAS that serve as jellyfin instance and store a hell lot of stuff. Things I would rather keep, but anything really critical is stored on several computers.
Works well so far (about 4 or 5 years already now) with raid5 for data but raid1 for metadata.
I tried it probably a decade ago and it ended badly.
The last time I checked it seemed like “the powers that be” running btrfs had shifted focus away from raid 5/6 because enterprises didn’t care about it.
Iirc there’s a big upcoming change that improves how btrfs works internally. This might improve btrfs raid 5/6. But yeah, currently it is recommended against btrfs raid 5/6