Problem: migrating 560GB data from 2013 iMac to new (2025) M4 mini with 500GB hard drive and 2TB external SolidStateDrive in a Satechi dock. Migration Assistant said "Not enough room to transfer" and cannot find the SSD. Ethernet transfer did 192GB and failed. USBa (old iMac) to USBc (M4) does not seem to connect. The iMac can ‘see’ my TimeMachine 2TB drive, why can it not ‘see’ the new SSD?
iMac 21.5″, macOS 10.15
LeesBetterLetters wrote:
USBa (old iMac) to USBc (M4) does not seem to connect.
If you are using Target Disk Mode, then the USB protocol is not an option if either Mac is running macOS 12.x+.....only Thunderbolt connections are supported.
Transfer files between two Mac computers using target disk mode - Apple Support
The iMac can ‘see’ my TimeMachine 2TB drive, why can it not ‘see’ the new SSD?
Did you erase the whole physical new SSD as opposed to just erasing the existing volume/partition? See this Apple article for details:
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
LeesBetterLetters wrote:
USBa (old iMac) to USBc (M4) does not seem to connect.
If you are using Target Disk Mode, then the USB protocol is not an option if either Mac is running macOS 12.x+.....only Thunderbolt connections are supported.
Transfer files between two Mac computers using target disk mode - Apple Support
The iMac can ‘see’ my TimeMachine 2TB drive, why can it not ‘see’ the new SSD?
Did you erase the whole physical new SSD as opposed to just erasing the existing volume/partition? See this Apple article for details:
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
Matti - I pretty much followed your suggestions: after erasing the M4, I copied my 'Old Jobs' and 'Photos' and 'Documents' onto a clean portable HardDrive and then pasted them onto the 2TB SSD in my Satechi dock. Then I ran Migration Assistant with those folders unchecked, and it brought over the apps (not perfectly - I'm still finding fonts and moving them into Font Book). I do use apple Mail (45GB of old emails!) and I would like to put it on the 2TB drive but I don't know if the app would work from there. //. And yes, it becomes clear that Time Machine will not back up external drives, so I may go back to CCC and a daily backup.
Manually copy all important user files via the Finder from the old Mac to an external SSD (formatted as APFS or MacOS Extended, GUID, case insensitive). Don't forget to copy also ~/Library/Mail folder in case you have used Mail.app in the old Mac -- you can then import that mail to the new Mail.app.
Then, if space permits, copy those user files to the new Mac.
Then continue making Time Machine, Carbon Copy Cloner, Super Duper etc backups from all drives.
...yes, Time Machine usually does all this automatically but sometimes manual gear is still needed...
Problem: migrating 560GB data from 2013 iMac to new (2025) M4 mini
