OpenZFS Lands Raidz Expansion Feature

"This feature allows disks to be added one at a time to a RAID-Z group, expanding its capacity incrementally. This feature is especially useful for small pools (typically with only one RAID-Z group), where there isn't sufficient hardware to add capacity by adding a whole new RAID-Z group (typically doubling the number of disks)."

Here's the commit message

https://github.com/openzfs/zfs/pull/15022/commits/c3f8a291b1...

Great work, though note that it will be available on 2.3 release estimated in 2024 https://github.com/openzfs/zfs/pull/15022#issuecomment-18024...

Amazing work by all involved! Thank you.

I initially thought that this was only affecting RAIDZ groups, but it looks like it also affects RAIDZ2 groups? Can someone confirm this?

  After the expansion completes, old blocks remain with their old
  data-to-parity ratio (e.g. 5-wide RAIDZ2, has 3 data to 2 parity), but
  distributed among the larger set of disks.  New blocks will be written
  with the new data-to-parity ratio (e.g. a 5-wide RAIDZ2 which has been
  expanded once to 6-wide, has 4 data to 2 parity).

Wow – this feature has been years in the making, it's great they've finally crossed the finish line!

wow congrats to all people involved it feel good to finally see this feature land