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how do you set up an external hard drive as the startup disk for imac 21.5" retina 4k, 2017

how do you set up an external ssd as the startup disk

iMac 21.5″, macOS 10.13

Posted on Jan 18, 2021 1:22 PM

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Question marked as Top-ranking reply

Posted on Jan 18, 2021 3:52 PM

Yes. What system are you using now?


Also I'd use Carbon Copy Cloner 


If you have trouble with CCC you can create a bootable flash drive according to this document and boot into it and select the SSD to install on: How to create a bootable installer for macOS - Apple Support






6 replies

how do you set up an external hard drive as the startup disk for imac 21.5" retina 4k, 2017

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