Hi Cleaning up my Macbook before I sell on and migrate to my new Mac when I noticed something a little odd with my external WD Thunderbolt Duo as it shows up in DiskUtility (see attached screenshot). Looking for a thread or guide to take me through how to repair this. Have found no one with a similar issue. Not sure if this was caused by upgrade to El Capitan. I upgraded the 8TB Duo to a 12TB version 6 months ago swapping out the two 4TB Reds with two 6TB Reds, set up the RAID 0 as before and it worked as with the 8TB version, one Disk with two drives noted and the single name in Disk Utility. As you can now see showing as three separate Disks. To be clear, the drive is functioning normally, Carbon Copy Cloner automatically backs up to my NAS from the Duo and has no issue accessing the drive and copying from it. All data on the drive is fine and no other issue other than the separation out of the physical and virtual disks. Tried the basics such as unmounting and remounting, switching external drive off, switching macbook off etc. No change. Any thoughts or pointers much appreciated.