macOS · Mac · Everyday fixes

Run First Aid on external drives

External drives fail quietly — files vanish, copies stall. Disk Utility's First Aid catches most problems while they're still fixable.

DifficultyEasy
Time10 min
RiskLow
ReversibleYes
PlatformmacOS
UpdatedAug 18, 2026

Written and tested by emdottech

What that means

Low risk. This fix only checks things, or changes settings you can switch back in the same place. This change is reversible — you can return to the previous state without professional help or data loss.

Disk Utility's First Aid on an external SSD that runs clean, a backup HDD where errors were found flagged to back up now, with monthly cadence and APFS or exFAT format notes

Steps

01
- Open Disk Utility (CmdSpace → 'Disk Utility'), select the drive in the sidebar and hit First Aid → Start
02
- If it reports errors it can't repair, back up what you can immediately — that drive is on borrowed time
03
- Mac-only drives should be APFS or Mac OS Extended; Windows-shared drives should be exFAT (check under 'Info' after selecting)
04
- Run First Aid monthly on any drive holding important data — ten minutes now beats a data-recovery quote later

How to verify the fix

First Aid completes with The volume appears to be OK (or repairs reported), and files copy without stalling.

If this didn't fix it

First Aid reports errors it can't repair — back up what you can immediately; that drive is on borrowed time.

Next stop: the related fixes below, or start a guided diagnosis.

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Run First Aid on external drives

Steps

✓How to verify the fix

!If this didn't fix it

Related fixes

How to verify the fix

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