How to Use Disk Utility First Aid on Mac

What Causes This?

Disk Utility First Aid on Mac is used when the file system on a drive has minor errors, usually caused by improper shutdowns, interrupted updates, failing storage hardware, or apps crashing while writing data. These issues can affect your startup disk, external drives, or USB storage and lead to slow performance or files not opening correctly. In many cases, clutter and low free space can also make maintenance harder by leaving macOS with less room to work during repairs.

Common Symptoms

• Your Mac starts slowly or freezes during boot
• Files or folders won’t open, copy, or move properly
• An external drive won’t mount or keeps disconnecting
• Apps crash when saving or opening files
• Disk Utility shows warnings or errors for a drive

How to Fix It Manually

1. Back up important files first

   • Before running repairs, copy important documents, photos, and project files to another drive or cloud storage.
   • If the disk is failing, repairs may not fully recover lost data.

2. Open Disk Utility

   • Click Finder > Applications > Utilities > Disk Utility.
   • You can also press Command + Space, type Disk Utility, and press Return.

3. Show all devices

   • In Disk Utility, click View > Show All Devices.
   • This lets you see the full drive, its container, and any volumes underneath it.

4. Run First Aid on the affected disk

   • In the left sidebar, select the volume or drive with the problem.
   • Click First Aid, then click Run.
   • Wait for the scan to finish. If prompted, continue with the repair.

5. Repair in the correct order if needed

   • If you see multiple items under the same physical disk, start with the volume, then the container, then the physical disk.
   • Run First Aid on each one if errors continue.

6. Use Recovery Mode for the startup disk

   • If First Aid can’t repair your main Mac drive while macOS is running, restart into macOS Recovery.
   • On Apple silicon Macs: shut down, then press and hold the power button until Loading startup options appears.
   • On Intel Macs: restart and immediately hold Command + R.
   • Open Disk Utility from Recovery, select the startup disk, and run First Aid again.

7. Check the results and restart

   • If Disk Utility reports the disk appears to be OK, restart your Mac and test the problem again.
   • If it says the disk can’t be repaired, back up data immediately and consider replacing the drive.

8. Free up space after repairs

   • Remove large unnecessary files, old downloads, and unused apps.
   • Keeping free space available helps macOS run maintenance tasks more reliably and reduces future disk-related issues.

Fix It Automatically with Kudu

If your real problem is low space, junk files, or clutter making your system harder to maintain, Kudu gives you an easier way to clean things up before and after disk repairs. It can quickly find unnecessary files, free storage, and help keep your PC or Mac running smoother without digging through folders manually.

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