Time Machine on a mac-mini M1 can't read the Time Machine backup disk of a mac mini 2010

Skipping Migration from the Time Machine backup during the initial setup was the first problem.

Leaving the Time Machine backup drive connected to the new Mac Mini was the second problem.

I can't say for sure without seeing your Mac Mini and Time Machine backup, but I'd say you now have two options.

1. Start completely over. Erase the reinstall macOS on the new Mac Mini. Erase the 2010 Time Machine backup and make a new 2010 backup. Then migrate from the 2010's Time Machine backup during the initial new Mac Mini macOS setup.
2. Make a new 2010 Time Machine backup and use Migration Assistant, which will end up giving you two User Accounts on the new Mac Mini. Then you can manually merge the info from the old 2010 Account into the new Mac Mini Account.

Paulus_2 wrote:

Thanks for your comments on my problem discription. I have n’t found any information from Apple that Time Machine backups from older Mac’s are not readable by the new Macintosh’s with the M1 processor. If so then it is an omission in information.

I am looking for a way to transfer - selectively - the content of my Documents folder from my Mac mini 2010 to my Mac mini M1 Documents folder.

I hoped to do that with my Time Machine backup disc.

I skipped the option during installation because of a missing cable to connect my Time Machine backup disc - a LaCie rugged 1 Terabyte disc - to my Mac mini M1 USB port.

You're welcome.

Migrating from Time Machine is pretty much all or nothing.

Maybe iCloud or the LAN network is a solution. Both Mac’s are operational on my local network. My Mac mini 2010 operates as a media server now on my LG TV. The files in the Document folder are available via Sharing through the network.

Moving files over your local network will work, but it's slow if you need to move a lot of data.

At this point tbirdvet has your best solution. It is much faster to copy what you want onto an external drive and then move that to the new iMac.

Paulus_2 wrote:

Thanks @tbirdvet and @den.thed.

The use of an external disk is familiar to me. But I do have copies of the files already on my Time Machine backup disk. So this is double work due to backup software that is not really compatible on two devices, on two different Macintoshes. That is something that should be written on the wall.

Time Machine is an all or nothing backup to restore or migrate from. If you want/wanted to pick and choose, then you should use a different backup strategy like a manually drag n drop backup or use cloning software like CarbonCopyCloner or SuperDuper.

But any way, thanks for thinking about my problem with Time Machine. The files are not that big so that a 1000Mb/s network (1000baseT) is a soring bottleneck. And I do not have to hustle with an external disc.

That's totally up to you. However IMHO now is as good a time as any to ditch Time Machine and move to another strategy that best sites your need.

You could just copy your old documents folder to an external drive then paste back into the new Mac. if that is all you need to transfer.