Use these commands to mount all of them or to unmount all of them in one go: X = the partition identifier, such as disk2s2.Ī disk can contain 1, 2 or more partitions. The Mac still knows it is there, you just can’t access it till it is mounted again. If a disk is unmounted it is removed from Finder and is no longer available for reading or writing. This makes it visible in Finder and allows files to be read and written to it. Mount and umount volumes and disksĪ disk that is internal or external can be seen by the Mac, but it cannot be accessed until it is mounted. So in my case it would be disk2, which is the identifier for the USB drive. To check that the disk is OK, in other words, that the partitions are correctly defined, and to repair faults use: They should not need checking or repairing. Apple says that permissions are protected and cannot be modified by the user. On old versions of OS X you could also use diskutil verifyPermissions x and diskutil repairPermissions x, but since El Capitan this feature has been removed. X = the volume/partition identifier, such as disk2s2 or disk2s4. There are commands for verifying that a volume is OK and for repairing faults: There is a lot of information there like the media type, SMART status if available, the filing system, size, whether macOS can be installed on it and so on. The identifier is disk2s2 and so the command is diskutil info disk2s2 Suppose I want a detailed description of the second partition on my external USB disk drive. The name is irrelevant, it is the identifier that is important. So disk2 at the bottom of the identifier column refers to my external USB drive and disk2s4 refers to a partition on it. When using the diskutil command, you use the name in the IDENTIFIER column on the right. Using the name and the size columns, you can work out which disk is which - internal, external, which partition and so on. Below each disk are the sizes of each partition. The third column shows the disk size *500.1GB for the internal disk and *500.1GB for the external USB disk. It is a bad choice for volume names when using diskutil from the command line because diskutil names disks disk0, disk1, disk2 and so on. These are the names under the disk icons on the desktop. The drive is partitioned into two and I named them Disk1 and Disk2. The external USB drive is called disk2 and at the bottom it has EFI, Disk1, Recovery HD and Disk2.
Recovery HD - used when booting the Mac and using recovery toolsīOOTCAMP - Windows 10 is installed on this Mac MacBook - the name of the disk volume on the internal disk On disk0 is:ĮFI - disk partitioning system area. The second box highlights the name of each disk. If you don’t have Boot Camp you probably won’t see a virtual disk. The disk1 (internal, virtual) is no doubt because of the way Boot Camp works. These are the internal and external drives I have. The first shows the physical drives and at the top is disk0 (internal, physical) and at the bottom is disk2 (external, physical). There are four highlighted boxes in the screenshot above. Most people's diskutil list display will probably look a lot simpler than mine. I also have a USB drive that is split into two partitions. The information you see may not look like mine because I have partitioned the internal boot disk and have installed Windows 10 using Boot Camp. Open Terminal in the Applications/Utilities folder and type diskutil list
In this article I will show how to use some of the basic functions of the diskutil command and show where you can get more information about it if you want to use some of the more powerful features. It does everything in Disk Utility and a lot more. It has a much wider range of functions and is a lot more powerful. There is another side to Disk Utility and the diskutil command is where the real power lies. The graphical user interface makes accessing the features and functions straightforward and easy. Learn the secrets!įor most tasks involving formatting, partitioning and erasing disks, the Disk Utility tool in the Applications/Utilities folder is recommended. However, there are many more features available from the command line. Disk Utility on the Apple Mac is a useful tool for formatting disks, partitioning them, and so on.