Install MacOS Tahoe on external SSD

Hello,

I am trying to install MacOS Tahoe on an external SSD to test my applications before updating my MacOS Sequoia. The external drive is correctly formatted (at the root of the physical drive). The installation does not complete! After the second restart, I am back on my Sequoia! When I try to continue the installation, my external SSD displays the following message: this volume cannot be used because it has a secure token without a user.

Thank you for your help.

MacBook Pro 14″, macOS 15.7

Posted on Oct 30, 2025 3:51 AM

Top-ranking reply

HWTech

Level 9

67,916 points

Posted on Oct 30, 2025 12:50 PM

You also need to erase the whole physical drive so that the partition table is rebuilt as well since sometimes the partitioning from the factory can cause problems (especially when used as a boot drive). See the following Apple article from the Internet Archive since Apple has changed & ruined the most recent version of the article:

https://web.archive.org/web/20250909095655/https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/mac

You are not using the proprietary Samsung software to manage that T7 SSD are you? If you have enabled the T7's builtin hardware encryption, then that can be a problem as well.

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17 replies

macdan67 Author

Level 1

8 points

Oct 31, 2025 10:27 AM in response to macdan67

I tried with another external SSD drive: the problem is the same. Tahoe won't install. For me, it only works with a normal 2.5-inch external drive (not SSD)! Any ideas for the SSD? Thank you.

macdan67 Author

Level 1

8 points

Nov 2, 2025 1:09 AM in response to HWTech

Thank you! I will take my Mac and the external drive to an Apple Store...

Install MacOS Tahoe on external SSD