I'm sick of the anemic performance of the Fusion drive in my late 2015 iMac.  The NVME component is just too small.  I'm upgrading to external SSD.

 

Starting with the Big Sur version of MacOS, Apple has made it difficult to create a bootable clone directly.

I got the instructions for this procedure from the Carbon Copy Cloner web site.

 

The procedure:

make a normal clone of iMac system drive to new SSD using Carbon Copy Cloner

download the current Big Sur installer from Apple App store

install Big Sur to the new SSD connected as external drive

migrate settings from the old install to the new install on SSD (unsure if this is possible)

 

I will then boot the SSD from my USB3 dock and run the SSD as my system drive.  Once that has been tested I will eventually upgrade the internal NVME and replace the internal spinner with the WD SSD.  I already have a new faster and bigger NVME, but it was packed away somewhere during my recent move from US to CM.

 

I've copied the Fusion drive contents to the SSD using the trial period of Carbon Copy Cloner.  I've downloaded the Big Sur installation app and will install to the SSD this evening.

 

Anyone else gone down this windy road to upgrade an older iMac?

If so are there difficulties I should be aware of?

 

42 minutes ago, gamb00ler said:

Starting with the Big Sur version of MacOS, Apple has made it difficult to create a bootable clone directly.

The reason is that there are now 3 partitions created, the restore, a locked system partition that is hidden and the data partition. This is to make attacks on the system much more difficult, that I also makes a bootable clone more difficult is purely a side effect. 

When Apple introduced the ADHD file system (oops, I meant APFS) things got much more complicated. However, the file system is much more flexible using containers now.

 

See description: APFS Containers, Volumes, and Partitions