"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

"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/c3f8a291b12aae4b6864b0e48652d05130e96fcf https://github.com/openzfs/zfs/pull/15022/commits/c3f8a291b1...