I find no scheme option in Disk Utility when I erase a hard drive on my Mac. It only allows me to name the disk and choose a format for it. I remember that there was a scheme option when reformating a USB drive before. What is the scheme in Disk Utility? Why can’t I find the scheme menu in Disk Utility? I want to change the drive with GUID Partition Map, how can I do that?
I have encountered the same issue before. When I format my external SSD, I find no scheme option in Disk Utility either. But later I found the cause of the issue. Disk Utility only offers the scheme option when you erase a physical drive rather than a volume on that drive.
Moreover, maybe you’ve never noticed that your Disk Utility only shows the volumes of connected disks on the sidebar. Therefore, you naturally choose the volume on the hard disk for formatting until you notice that there’s no scheme option.
You need to click the View button on the toolbar of Disk Utility and select Show All Devices to display all the hard drives and volumes. Then, select the entire external hard drive (on the sidebar, it’s the top level under the words External). Now, click erase you’ll see the scheme option.
Here are the steps about how to change the partition scheme on Mac:
-
Go to Finder > Applications > the Utilities folder > Disk Utility.
-
Click the View button on the top toolbar and choose Show All Devices.
-
Select the entire external hard drive and click Erase.
-
Type a name and choose a format and scheme (GUID Partition Map, Master Boot Record, Apple Partition Map) for the drive.
-
Click Erase.
1 Like
The scheme in Disk Utility refers to the partition map scheme. It stands for the method used to define and manage partitions on a storage device such as a hard drive.
A scheme determines how the storage space on the drive is divided into separate areas (partitions), how the partitioned areas (partitions) can be managed and formatted independently, and how the operating system maintains these partitions.
A partition map scheme usually contains information about the partition sizes, locations, and types of each partition. Each physical hard drive must be partitioned and assigned a file system before being used to store data.
There are three partition schemes in Mac Disk Utility by default, including GUID Partition Map, Master Boot Record, and Apple Partition Map. GUID Partition Map is the common partition scheme that is used on modern macOS and Windows.
1 Like
I have some supplementary opinions. If you choose to format the physical hard drive but still find no scheme option in Disk Utility, restart your Mac, boot your Mac into Safe Mode to exclude all third-party apps or check and uninstall any suspicious third-party disk formatting tool.
I learned that some third-party disk formatting software has conflicts with the built-in Disk Utility. That may be a troublemaker causing you to not see the scheme menu. If no luck, you have to try to update your Mac. System bugs often cause improper performance on your device.
Which partition scheme should I choose? I prepare to format the external drive to APFS and choose the GUID Partition Map.
Your choice is right. GUID Partition Map is the primary partition option for hard drives on modern Mac machines that replaced Master Boot Record (MBR). It is often used on modern Windows PCs, but on Windows, it is GUID Partition Table (GPT). Here are details of: MBR vs. GPT and GUID Partition Map vs. Apple Partition Map.
I’ve checked in Disk Utility. It’s true that my Disk Utility sidebar only shows volumes and I mistakenly regard that the volume is my physical hard drive.