Setting up JBOD, all SATA, a couple of drives just aren't recognized in BIOS/PERC

Hi,

There are circumstances that PERC can recognise hard drives which are not Dell drives, but there are times when it doesn't. Have you tried swapping the drives to other slots on the server? Or the detected drives to the slots where the 12TBs are, to confirm slot has no issue. 

When the drives are slotted in, does the LED blink or any signs? Perhaps, you might need to look into PERC logs/TTY Logs to check if there are any errors or root cause. We don't look at logs here in the community, but if you do find any errors in the log, you can paste it here, and we'll try to look for that error message solution. 

Perhaps, to troubleshoot the issue, here are some Dell DPN# for 12TB drives which I found under searching for PowerEdge R730:

0JHTD 12TB, HDD, 7.2K RPM, 3.5 inch, Encrypted FIPS 140-2, SAS12, 512e, Enterprise Class  
0N96X 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SAS12, 512e, 256MB, Enterprise Class  
753F0 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SATA, 512e, 64MB, Enterprise Class  
9HXK6 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SAS12, 512e, Enterprise Class, Hitachi-L12 
DK7C9 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SAS12, 512e, 64MB, Enterprise Class  
KTJTY 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SATA, 512e, 256MB, Enterprise Class  
M1C0T 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SAS12, 512e, 256MB, Enterprise Class  
T2YHT 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SATA, 512e, Enterprise Class  
THPV0 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SAS12, 4kn, Enterprise Class  
V308G 12TB, HDD, 7.2K RPM, 3.5 inch, Non Encrypted, SATA, 512e, 256MB, Enterprise Class