Switched to External SSD... Not showing in startup disk

[spector]

I have a 21.5 2017 iMac that i just got a 500 gig Sandisk SSD today for. I cloned my mac drive using carbon copy cloner, I then restarted and got booted into the ssd copy but then went to the startup disk and my external drive is not showing just my internal mac drive is showing up.... did i miss a step???

 

[spector]

I had my external formatted incorrect was the end result... reformatted and reflashed with the cloned version and all is good.

 

[gfbaldin]

I had my external formatted incorrect was the end result... reformatted and reflashed with the cloned version and all is good.

When you say you had it formatted improperly what did you do to fix. I think I’m having the same problem. I can boot the new SSD but cannot select it to be the main boot drive under start up disk.