X-Raid Verticle Expansion Incomplete

Hello,

I have recently attempted a Verticle Expansion of our array from X-Raid (6) 12X3TB by

replacing with 4X6TB drives.  I replaced one drive at a time allowing amply time to resync, verifying online in the logs for each.  On the 4th drive, upon completion, I had expected the volume to expand;

however, the following resulted

"Remove inactive volumes to use the disk"

Several reboots later and firmware update i am not much farther ahead.

Is this normal and what have others done in the community to deal with this?

  Firmware 6.9.3

Regards,

Dave