Pool with parity? ZFS? RAID5?

[thany]

Bit of an odd title, but here's the situation. Brand new server, brand new installation of the latest stable unRAID. I've created a pool of 4 500GB SSD's. They are not identical, but very comparable.

 

After creating this pool, I was really confused by 2 things:

1. I was not presented any settings by which to construct this pool. Sane defaults, I would hope, and the ability to change them later.

2. The pool's total capacity is 1TB, but I expected roughly 1.5TB.

 

Turns out both are answered when going into the settings of any disk that is part of the pool. It's Btrfs, and by virtue of being unfamiliar with it, I guess it's fine. But it also says it's in RAID1 mode. I was hoping for something more like RAID5, which it says is experimental. I went for it anyway, seeing how this is a new server with empty disks anyway, and hoped for the best. The UI went totally nuts for a little while, but stabilised and not the pool is in RAID5 mode.

 

Alright. Question time.

 

1. How experimental is this RAID5 mode actually? I can't find any concrete information on this. Will this be "stable" in like the next release or something? Then I might be okay with it.

2. As the title suggests, I was hoping for a ZFS pool, because RAID-Z seems to be fully matured, and more flexible. Is there any way I can do this?

Edited October 7, 2022 by thany

[JorgeB]

12 minutes ago, thany said:

1. How experimental is this RAID5 mode actually? I can't find any concrete information on this. Will this be "stable" in like the next release or something?

btrfs raid5/6 has been experimental for many years, I've been using in multiple pools without issues for many years, but there are some known issues still, though most serious ones have been fixed, so make sure you have good backups, but you should have good backups anyway.

 

15 minutes ago, thany said:

As the title suggests, I was hoping for a ZFS pool, because RAID-Z seems to be fully matured, and more flexible. Is there any way I can do this?

For now you can use the ZFS plugin to create and manage pools, it's expected that official support will be present in Unraid's next release (v6.12)

[thany]

Sounds good! Thanks! I'll try the ZFS plugin. And also, I really hope there will be a solid migration path from the plugin towards builtin support, if needed.