Sounds like the VID (Virtual Install Disk) is enable in NVRAM. The VID is read only and will appear to the OS as a disk. Go into RBSU and disable the VID.
Advanced Options - Advanced System ROM Options - Virtual Install DIsk
Sounds like the VID (Virtual Install Disk) is enable in NVRAM. The VID is read only and will appear to the OS as a disk. Go into RBSU and disable the VID.
Advanced Options - Advanced System ROM Options - Virtual Install DIsk