You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Correct External SSD format, using as startup disk

Hi everyone

My ageing iMac 27inch is slow, so I want to use an external SSD as the main startup disk. What is the correct format please?


I’m running Big Sur.


Thank you!

Tony

iMac 27″, macOS 11.6

Posted on Dec 4, 2021 2:38 AM

Reply
Question marked as Top-ranking reply

Posted on Dec 4, 2021 2:42 AM

Welcome to Apple Support Communities.


Simply follow these steps: How to Setup and Use an External SSD as y… - Apple Community.


Also, what year is your iMac and what external SSD are you using?


Jack

6 replies

Dec 8, 2021 8:47 AM in response to Jack-19

Hi again Jack

SSD external drive not visible in SysPrefs



I made sure to format the external SSD as APFS, but it's still not visible in System preferences>Startup Disks. I've read that the standard approach is to restart and press CMD+R, then choose the SSD as a startup disk.


BUT, when I do this, the iMac just restarts as normal - there's no option to select the startup disk. I'm running Big Sur 11.6.1


Can you suggest what's happening and how to rectify the situation?


Many thanks

Tony

Correct External SSD format, using as startup disk

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.