Sadly enough, the current answers are to either do what you did, or replace disks one by one. RAIDZ expansion is coming though[0]. This is the right answer to

Sadly enough, the current answers are to either do what you did, or replace disks one by one. RAIDZ expansion is coming though[0]. This is the right answer to your problem, but an answer at some point in the future doesn't help you with your problem today. [0] https://www.bsdcan.org/2018/schedule/events/960.en.html https://www.bsdcan.org/2018/schedule/events/960.en.html