Hello,   No unlock code at all.  It's hard coded in the firmware itself.  Non EQL drives will be flagged and unused.  Don  
Hello, one of the disks in our Dell PS6000 told us it has a failure. To reduce the risk, we want to replace it. The current used Disk (Seagate ST31000340NS) are EOL Which kind of Disks we could use, because we think this disks needs a special Dell-Branded Firmware.  Thank you Uwe
PS6000 - New Disk needed