Migrating from Mac to a Mac with a different internal/external drive set up

My current iMac boots and stores data on one external 500GB SSD. I intend to migrate to a new Mac which will boot from an internal 256GB SSD, and store data on an external SSD.

Does anyone have any suggestion or recommendations as to the best way to do this? Does the migration assistant allow you to migrate system, apps and data from/to different disks in this way?

I’m nervous about manually copying data as I’ve got into a pickle previously with user permissions and copied files not having permissions for the user directory they were copied into, so I’m keen to understand if the safest way to do this with a migration tool.


Could you clone your external SSD to the internal drive (I’m assuming a Fusion Drive) using something like Carbon Copy Cloner, and then migrate from the internal drive?

Thanks. I have edited my original post with the fact that the new SSD (256GB) is smaller than the original (500GB) one. So that wouldn’t work unfortunately.

The principal of your advice would work - I could use CCC to separately copy the system and the data to the new SSDs. But I would be nervous about this (problems with permissions issues of data files if moved separately from system files?) so was wondering if the migration tools was a feasible safer option.

Gotcha! I wouldn’t know about using migration assistant unfortunately since I have never used it. But I imagine somebody else will chime in who has more experience than me.