[kylegordon]

> It really surprises me that zfs apparently cannot do this.

Likewise. I really want to like ZFS, but with the 'buy twice the drives or risk your data' approach as above really deters me as a home user.

ZFS has been working on developing raidz expansion for a while now at https://github.com/openzfs/zfs/pull/8853 but I feel that it's a one-man task with no support from the overall project due to that prevailing attitude.

BTRFS is becoming more appealing, even though it has rough edges around RAID write holes that really isn't a big deal, and reporting of free space. I can see my home storage array going to BTRFS in the near future.