TC-how to backup multiple drives

[MattDSLR]

OK here is a scoop
I have installed 3 tb Geen drive in MP for TC
I want to use the entire drive as a back up
problem I want to back up two 1 TB drives
one is my system
the other is all my photos
I can get one backed up but not the second drive
any inside on how to use both it would help
THX

 

[simsaladimbamba]

Have you made sure the second HDD is not excluded via System Preferences > Time Machine >> Options?

 

[MattDSLR]

no its not excluded