Need help with partitioning external disk


I have purchased a 4 TB Seagate external hard disk and would like to partition it to have 1 TB for Time Machine backups and the rest for files storage. says:

If you’re setting up the drive from scratch, or don’t mind wiping your Time Machine backups and starting over from scratch, you can also do that. Open the Partition tool for the drive, then delete any partitions that exist. Create two clearly labeled partitions, choosing Mac OS Extended (Case-sensitive) for the Time Machine partition and ExFAT for the file storage partition.

The problem is that the + button to create partitions is disabled.

Do I need to

  1. change the format from NTFS to another? If so, which one in this list?

Is it “Mac OS Extended (Case-sensitive, Journaled)” or “Mac OS Extended (Case-sensitive, Journaled, Encrypted)”?


  1. click Erase, give it a name and select a Format?