Thanks to an email from russell and a bit more head scratching, I think I've got it sorted. The problem I was encountering was the result of the BIOS on the Z400 which does "magic" to help the ignorant remain ignorant.
The key was to pull my mirrored scratch space disks and install the replacement drives in those bays. Then go through the usual boot, press F1 cycle. Once I'd done that then it sees the new drive and normal procedure seems to work. It's merrily resilvering the first new disk. zpool offline <pool> <device> zpool replace -f <pool> <old_dev> <new_dev> (-f to satisfy the presence of a traditional full disk s2 slice) zpool online <pool> <device> I had considered setting up an array at the drive capacity of the Z400. The BIOS behavior would likely make that catastrophic by requiring that the system be rebooted with both the old and new drives in place, but nowhere to plug in the new drive. The moral of the story seems to be, never use all of your disk ports. Leave at least 1 empty. _______________________________________________ openindiana-discuss mailing list email@example.com https://openindiana.org/mailman/listinfo/openindiana-discuss