In another post I was strongly discouraged to try to go through the gymnastics of upgrading a mirror pool to an RAIDZ2 pool by adding two disks to the two-disk mirror I currently have.
So, what about adding two new drives into the two empty bays of my four-bay and two more new drives into a docking station connected through USB-3? I would make the four new drives into a RAIDZ2 pool, which I would like to use to clone the mirror pool to. The goal of this would be to be able to disconnect the mirror pool and have the RAIDZ2 pool take on the role of the mirror pool.
Don’t do it Like 3 posts in the last week or two with people unable to make pools on USB docks, long time known & unsupported.
What motherboard are you using? Any chance you have any pcie slots that can use a real HBA? If not, I guess the least improper way would be move all data to single disk, create raidz2 pool, copy data to raidz2 pool, destroy single disk, expand raidz2 pool. 98% of those steps can be done using the GUI at the very least…
Like 3 posts in the last week or two with people unable to make pools on USB docks, long time known & unsupported.