[kwlug-disc] TrueNAS scale (4-5 drive configuration)

[Doug Moen]

> This functionality is reportedly "coming soon", ...

Wow, I didn't realize that RAIDZ Expansion is *still* coming soon.
* In June 2021, Ars Technica announced that "Matthew Ahrens opened a pull request last week" and that "RAIDz expansion will be a thing very soon".
* In November 2023, Phoronix announced that the PR was merged into master. <https://github.com/openzfs/zfs/pull/15022>

More discussion in <https://github.com/openzfs/zfs/discussions/15232>
* Sep 8 2024: Yes, special thank you to everybody on the OpenZFS side who helped get this one over the finish line. We've got this in our TrueNAS 24.10 BETA1 release already for testing, anticipating updating to OpenZFS 2.3 as soon as it is tagged.

So we can update the ETA to Very Soon.

>From Chris Irwin,
> I'm using 4x 8TB CMR NAS drives, and went for RAIDz1, which is kinda 
> like ZFS's version of RAID5 -- so n-1 drives worth of storage.
>
> That gives me 21.01TiB (8TB drives actually 7.28 TiB) of storage.

I read something concerning in the final discussion page I linked to.
@yorickdowne said
> Raidz1 with larger drives has a tendency to break during resilver.
> With 14TB disks raidz-1 is risky when rebuilding. I recommend you do a 4-wide raidz2, which you can then expand later if desired.