Fixed disks can include internal hard drives, but can also include portable devices such as external hard drives which connect via USB, FireWire, etc. MacDrive fully supports GPT partitioning for fixed disks. When formatting Mac-formatted disks, such as HFS+ or HFS+J, in Disk Utility, current versions of the Mac OS typically use GPT as the default partition type. GPT (GUID Partition Table) is a partition type for disks.