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Disk Utility is a built-in app in Mac that you can use for managing, formatting, and erasing internal disks and external storage devices. It can also diagnose and repair disk issues, troubleshoot external drives, and create disk images of files that you want to archive, transfer, or backup. Here’s what you need to know about using Disk Utility on your Mac.
What Can You Use Disk Utility For?
- Erase, format or manage internal disks and external storage devices
- Add or manage volumes, partition your data or create disk images
- Combine multiple disks into a RAID set that acts as a single disk to improve performance, reliability, and storage space
- Diagnose and repair disk and volume issues
Why Use Disk Utility?
You might want to use Disk Utility when:
- Your computer doesn’t start up
- An external device doesn’t work
- Your apps stop unexpectedly or you have a broken file
- You need to mount, unmount, or eject a disc
- You need to change the file system or partition a disk
- You suspect there’s a problem with your startup disk or you need to repair a disk
How to Verify and Repair Your Disk With Disk Utility
If you think there’s a problem with the disk on your Mac or an external storage device, you can use the First Aid feature in Disk Utility to check and repair it. Here’s how:
- Open Disk Utility and select the device you’re having issues with in the sidebar
- Click on First Aid
- Disk Utility will check the partition cards, and if it detects a problem, it will attempt to repair it
If Disk Utility detects that the disk or volume is about to fail, you should back it up and replace it.
How to Repair Disk Permissions
To ensure applications can access files correctly, it is important to set the correct permissions for files. Here’s how you can repair the permissions:
- Open Disk Utility and select the startup disk from the list of volumes
- Click on the First Aid tab
- Click Check Disk Permissions to check the permissions. Click Restore Disk Permissions to restore permissions.
How to Create a Disk Image with Disk Utility
You can use Disk Utility to create a disk image of the contents of a folder that you can transfer or archive to another Mac. Here’s how:
- Open Disk Utility and click on File and then New Image
- Select the folder you want to create a disk image of
- Choose a format for the disk image, such as read/write or read-only
- Choose a location to save the disk image and click on Save
How to Format a Disk with Disk Utility
You might need to format a disk to erase all data on it, encrypt it or create multiple partitions for different operating systems. Here’s how:
- Open Disk Utility and select the disk you want to format
- Click on Erase and choose the format you want for the disk
- Enter a name for the disk and click on Erase
Additional Tips for Troubleshooting with Disk Utility
- If you can’t mount a hard drive or flash drive on your Mac, here’s what to do
- If you want to partition a disk, learn how to partition a Mac right here
- If your startup disk needs repair, you need to boot your Mac into recovery mode and repair the disk from there
FAQs
What is the purpose of using Disk Utility?
Disk Utility is used for managing, formatting, and erasing internal disks and external storage devices. It can also diagnose and repair disk issues, troubleshoot external drives, and create disk images of files that you want to archive, transfer, or backup.
How do I diagnose disk problems with Disk Utility?
To verify and repair your disk with Disk Utility, open the app and select the device you’re having issues with in the sidebar. Click on First Aid, and Disk Utility will check the partition cards, and if it detects a problem, it will attempt to repair it.