My 2013 27" on Catalina 10.15 is running out of disk space. The internal 3TB HDD is broken and I have kept it working by splitting the fusion drive and running it off the still functioning but very small internal128GB SSD.

In order to download a new OS and create an installer, I decided to use Carbon Copy Cloner to clone the install onto a new 480GB SATA SSD, connected via a USB to SATA adapter.

The CCC process went smoothly and it created a clone in about 25 minutes.

When I try to boot from from the clone, the SSD is recognised at the boot picker stage (holding down the ALT/OPT key on boot) and it begins to boot but when the progress bar has gone about 3/4 of the way across the iMac just shuts down.

I have used CCC for years and always found it super reliable. Has anyone got any tips on how to troubleshoot this one?

  • Trying to follow along…what exactly did you clone to the new SSD? Why not repair properly (take off the glass and install the drive) then recreate the Fusion drive. This seems convoluted.
    – Allan
    Jan 31 at 19:42
  • I don't want to take the iMac apart, the screen is glued in. I needed to make an installer and didn't have enough storage. Feb 2 at 6:49


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