---
id: external-drives.how-do-i-run-first-aid-on-an-external-drive
url: https://storagestudio.us/faq/external-drives/how-do-i-run-first-aid-on-an-external-drive
category: "External drives"
subcategory: "Checking your drive"
question: "How do I run First Aid on an external drive in Disk Utility?"
alt_questions:
  - "Disk Utility First Aid external drive"
  - "Repair external drive Mac"
  - "How to fix a corrupted external drive on Mac"
  - "Run First Aid on USB drive"
  - "check and repair external SSD macOS"
  - "First Aid on container or volume?"
short_answer: "Open Disk Utility, choose View → Show All Devices, select the drive's volume and click First Aid → Run. For a full check, run it on each volume, then the container, then the device. It repairs file-system errors, not failing hardware."
tags: ["disk utility", "first aid", "repair"]
related: ["https://storagestudio.us/faq/external-drives/how-do-i-check-an-external-drive-for-errors", "https://storagestudio.us/faq/external-drives/first-aid-cant-repair-my-external-drive", "https://storagestudio.us/faq/external-drives/my-fast-drive-is-failing-what-should-i-do"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# How do I run First Aid on an external drive in Disk Utility?

Open **Disk Utility**, choose **View → Show All Devices**, select the external drive's volume in the sidebar and click **First Aid**, then **Run**. First Aid checks the volume's structure and repairs the errors it can. Close apps using the drive first.

For the most thorough check, run First Aid in this order: each **volume** on the drive, then the **container** (on APFS drives), then the top-level **device**. Each level checks something different.

What the result means:

- **"appears to be OK"** — nothing to fix.
- **Repaired** — run it once more to confirm it now passes.
- **Couldn't repair** — copy anything important off the drive straight away, then consider erasing it. See [what to do if First Aid can't repair it](https://storagestudio.us/faq/external-drives/first-aid-cant-repair-my-external-drive).

First Aid checks the file system, not the hardware. A drive that keeps needing repair may be failing — see [checking a drive for errors or health problems](https://storagestudio.us/faq/external-drives/how-do-i-check-an-external-drive-for-errors).