How do I unlock a 2TB USB drive on macOS High Sierra?

Question

Level 1

4 points

How do I unlock a 2TB USB drive on macOS High Sierra?

it is locked and I've tried every thing to open it. I have high sierra and it mounts but I cannot save any thing on it. It has been Mac formatted and it works but just cannot save to it.

[Re-Titled by Moderator]

Original Title: external 2TB usb drive

MacBook, macOS 10.13

Posted on Jun 6, 2025 3:07 PM

Reply

Answer 1

Tesserax

Level 10

156,108 points

Jun 7, 2025 10:59 AM in response to lubyd

Based on what you posted, it appears you're running into a permissions issue on your 2TB USB drive. If the drive mounts and you can open it but not write to it, it's likely either locked via permissions or there's an issue with its format or disk flags.

Let's start by verifying how this drive is formatted: either as Mac OS Extended (Journaled) or APFS. To do so:

Open Disk Utility
Select the drive from the sidebar and look under the Format field.

Next, let's double-check the drive's permissions.

Right-click the mounted USB drive on the desktop or in Finder and choose Get Info.
At the bottom of the window, check the Sharing & Permissions section.
Make sure your user account (or “everyone”) has “Read & Write” access.
If it shows as locked or permissions are wrong, click the lock icon (bottom right), authenticate, and adjust the permissions.
While still in the Get Info window, check the box for “Ignore ownership on this volume”.

If it's not checked, and you can’t change it, run the following command in Terminal: (Note: Replace YourDriveName with the actual name of your USB volume.)

sudo diskutil disableOwnership /Volumes/YourDriveName

Reply

Answer 2

lubyd Author

Level 1

4 points

Jun 7, 2025 4:25 PM in response to Tesserax

Thanks 4 all your help. It IS a permissiona issue with high sierra because my other external drives function flawlessly. I'm trying to back up all my data b4 the logic board goes out. I need my data on my new Mac. I've done every thing u've written and all of that is done. I can even unlock the lock. I did 1 last info check and I see the issue. It reports that only 6.1MB is used by the app and that there's 0 space on this 2tB drive. This is why I'm getting the block icon on the smallest things I'm test copying. It's Mac extended formatted but the app got stuk when formatting or erasing the drive and now it reports there's zeero space on the drive. That explains why I can copy any thing there. I just need about 400GB for all my stuff to b copied. Please help, aid and advise.

Reply

Answer 3

Jun 7, 2025 5:51 PM in response to lubyd

Given you’re running a flaky macOS 10.13 configuration, best reformat it using Disk Utility, and select HFS+.

That’ll erase everything, and will resolve whatever is happening with the USB storage and its protections.

Reply

Answer 4

lubyd Author

Level 1

4 points

Jun 8, 2025 12:24 PM in response to MrHoffman

OK the logic board is not going out. I have 10.13.6 - I have Commander 1 app but how to i re-format the drive in the system u've recommened? With both apps the erase or format buttons r greyed out. I cannot re-format this external drive because it is locked some how under high sierra. What do I do now and next?

Reply

Answer 5

Jun 8, 2025 1:16 PM in response to lubyd

Commander One is an analog to Finder. If you’re having issues with that app — and not with Finder — then check with the Commander One support people.

If Disk Utility is not allowing a reformat of the entire device, that may well mean the storage has failed, or maybe some vendor add-on app has failed. See of the storage vendor has diagnostics available.

Reply