HPE ProLiant DL385 Gen10 Plus v2 Maintenance And Service Manual page 142

When the front 24 SFF bays are populated, any installed rear 2 SFF drives are always 25 and 27.
Universal media bay Universal media bay
If a 2 SFF drive cage is connected to SAS expander port 3, then the drive numbers are 1 and 3.
8 LFF front panel 8 LFF front panel
12 LFF front panel 12 LFF front panel
Midplane box (LFF) Midplane box (LFF)
HPE ProLiant DL385 Gen10 Plus v2 Server Maintenance and Service Guide 142