I have a storage pool aptly called
storage with two disks in it. Originally, I wanted to add the second disk as a mirror but did the ZFS newbie mistake of using
zpool add storage <device> instead of
zpool attach storage <device>.
Every attempt to
detach the second device from the pool fails, because ZFS complains about not having redundant drives. After reading into it, I understand the issue and why this is. However, I wasn't able to find a solution how to either remove the drive to re-attach it or simply convert the whole pool to mirrored instead of striped. I'm also kind of puzzled by the fact there seems to be no straight-forward way to do it.
Is there a way to achieve this short of destroying and recreating the pool? I'd rather not need to buy another 4TB drive and copy all that data over.