How do I set up an external storage device to copy 1 tb of storageon my old mac mini to a new one with 256gb storage with migration assistant
You can’t.
You’ll have to buy a Mac with a larger drive, or.... copy and keep your user music, movies and photos on the external drive and access your user data from it.
Caution to be safe, you really need two external drives. One to move your user data onto and a second to backup the first.
By re-writing Migration Assistant to know what you yourself specifically want to keep and what you want to delete. Migration Assistant doesn't know what you want to keep and what you want to leave.
In more practical terms, you either need an equal or larger target for the migration, or you need to reduce the volume of data to be migrated.
Or you're going to want to configure external storage with a terabyte or more, and install and boot and use that.
Hosting your files in iCloud Drive might be an alternative, but that assumes you have a network connection that is both fast and stable, and that you are willing to rent what will probably be a terabyte or more of iCloud Drive storage from Apple for this usage.
That 256 GB configuration might be useful for someone with very limited storage requirements, or for students in a school classroom, or for a dedicated kiosk, or other similar storage-constrained usages. Or for someone that uses iCloud Drive to host their Mac files. For local usage, most of us will blow through that 256 GB configuration pretty quickly. You already did.
As for that system folder usage, boot into Safe Mode and see if that cleans up and by how much.
Thanks for the reply. The system folder on my old Mac is 805gb. Where will that go?
Thanks. I'll try the safe mode
copying 1tb to 256 gig
