I am migrating from a backup of a dead iMac to a smaller storage M1 Mac mini. There is only enough space to migrate network and applications. I really, really need to migrate my documents and other folders! Is there a way to select more than one target, say the new mini for applications and network, and a separate drive for the rest?
iMac 27″, macOS 10.14
No. Migration migrates to the same storage as macOS is installed.
Move your content to a new Mac - Apple Support
Depending on how much storage was configured with that iMac...
Return your Mac and purchase one with more internal storage (returns with refund are usually possible within 14 days of purchase), or connect and configure and boot from external storage, or figure out what you don’t need and delete it.
Mac mini can be configured with up to two terabytes of internal storage at purchase. No internal storage upgrades are available after purchase. Substantially more external storage is possible to acquire and configure. One Mac mini I occasionally deal with has 64 terabytes configured, when last I checked.
No. Migration migrates to the same storage as macOS is installed.
Move your content to a new Mac - Apple Support
Depending on how much storage was configured with that iMac...
Return your Mac and purchase one with more internal storage (returns with refund are usually possible within 14 days of purchase), or connect and configure and boot from external storage, or figure out what you don’t need and delete it.
Mac mini can be configured with up to two terabytes of internal storage at purchase. No internal storage upgrades are available after purchase. Substantially more external storage is possible to acquire and configure. One Mac mini I occasionally deal with has 64 terabytes configured, when last I checked.
There have been some success stories, dealing with installing and starting up the M1 from a larger external SSD.
https://eclecticlight.co/2020/12/22/booting-an-m1-mac-from-an-external-disk-it-is-possible/
https://discussions.apple.com/thread/252158270
Basically you would need to setup an external SSD as the startup disk for the M1 and then migrate the old dead iMac's backup to it. Then after that, you could go back to starting up from the M1's drive and access your migrated data on the external SSD.
Another option, is to pull the HDD out of the old iMac and put it into a USB External Drive Enclosure. Then access and/or manually copy what you want from the old iMac drive to the new M1.
A work around I can envision is to take my 2009 Mac mini and "restore" the files and folders to that computer, not touching the OS, then copy them to a location I desire.
Migration complicated because of smaller new computer drive
