2017 21.5" iMac HD clone to external SSD

[FUKTARD]

If anyone can confirm this course of action and answer the questions I'd greatly appreciate it.
I would like to use an external SSD via USB-C as the main drive with OS and apps, and the original internal HD as storage.
(iMac 2017 21.5" Big Sur)

Course of action:
1. Using disk utility, clone internal HD to external SSD.
2. Use USB-C to boot from external SSD.

Questions:
1. Do all files and apps remain working as they did?
2. Does the internal HD show up (on desktop or in finder), and therefore can be erased for use as additional storage? Without taking it out of the imac?

Thanks!

 

[Fishrrman]

Yes, it will work.
However, I don't think disk utility can do "a clone" of Big Sur.

The latest version of CarbonCopyCloner CAN do it.
CCC is FREE to download and use for 30 days.

You DON'T want to pry open an iMac "just to take the HDD out".
Leave it there to be "an internal backup".
Or "re-purpose" it.
(and get yourself a new screen name while you're at it)