Managing Drives with Disk Utility on macOS Tahoe
Disk Utility is the native tool in macOS Tahoe for managing internal and external storage devices. You can use it to format drives, repair file system errors, and manage partitions.
Opening Disk Utility
You can find Disk Utility in the Utilities folder within your Applications, or simply search for it:
- Press
Cmd + Spaceto open Spotlight. - Type "Disk Utility" and press
Enter.
First Aid: Repairing Disks
If a drive is acting up, files are corrupted, or your Mac is crashing, "First Aid" is the first step.
- Select the disk or volume you want to check from the sidebar.
- Click the First Aid button (stethoscope icon) in the toolbar.
- Click Run.
- Disk Utility will lock the drive and check for errors. If it finds errors, it will attempt to repair them automatically.
Note: You cannot run First Aid on the startup disk while you are using it. To repair your startup disk, you must restart your Mac in Recovery Mode.
Formatting (Erasing) a Drive
To prepare a new external drive or wipe an old one, use the Erase function.
- Select the external drive in the sidebar.
- Tip: If you don't see the physical drive, click View > Show All Devices.
- Click the Erase button in the toolbar.
- Name: Give your drive a name.
- Format: Choose the file system.
- APFS: Best for SSDs and flash drives used only on Macs.
- Mac OS Extended (Journaled): Best for older mechanical hard drives used only on Macs.
- ExFAT: Best if you need to use the drive on both macOS and Windows.
- Scheme: Choose GUID Partition Map.
- Click Erase.
APFS Volumes vs. Partitions
macOS Tahoe uses the Apple File System (APFS). Unlike older systems where you had to slice a disk into fixed-size "Partitions," APFS uses "Volumes" inside a "Container."
- Partitions: Fixed size. If you make a 50GB partition, it takes up 50GB even if empty.
- APFS Volumes: Flexible size. Multiple volumes share the same pool of free space.