David Myers wrote:
I have a 2011 iMac 21.5 in. running 10.13.6. It has been running a bit hot?lately, so I need to take it apart to clean it out. I also need to clean the?screen on the inside because of a large clouded area. I have decided to?replace the hard drive with a SSD drive when its apart. I have 2 questions.?What format to use on the new drive? And how to get the iMac to boot up?to my clone backup when I first start it up? I found some conflicting?answers on a few web searches and just want to be sure.??
Your machine appears (Mactracker) to have a 3.5¡± form factor hard drive; SSD¡¯s come in laptop-size, 2¡± form factor, so it will need an adaptor to fit properly.?
See iFixit:
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Have you ever booted from the clone backup before?
Better make sure you have no problem doing that.
Restart your machine, and as soon as the ¡°bong¡± occurs, press and hold the <Option> key until the screen comes up showing all the available bootable drives. Select the clone drive and press <Return>
It should boot from the clone.
At this point, I would set up the SSD for APFS whether the system requires it or not
I presume your plan is to clone the clone back to the SSD
Jim Saklad