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bill99

macrumors regular
Original poster
Aug 16, 2019
109
7
Hi

Would like to be able to install Catalina to my iMac 2019 from a bootable offline installer media (USB)
without "Internet-Recovery" or other approaches. E.g for the case of an SSD-crash.

Therefore I did download the 8.25GB Catalina offline installer from:
https://apps.apple.com/au/app/macos-catalina/id/1466841314?mt=12


imac-admin@imac-admins-iMac /volumes % sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

Password:

Ready to start.

To continue we need to erase the volume at /Volumes/MyVolume.

If you wish to continue type (Y) then press return: y
Erasing disk: 0%... 10%... 20%... 30%... 100%

Copying to disk: 0%... 10%... 20%... 30%... 40%... 50%... 100%

Making disk bootable...

Copying boot files...

Install media now available at "/Volumes/Install macOS Catalina"



After booting the Mac with Command-R, "Startup Disk" says:

- "You can't change the startup disk to the selected disk"

and

- "The bless tool as unable tp set the current boot disk"



Question:
What am I doing wrong?


Thank you very much for any help!


Bill






PS:
- by the way, I was able to boot this iMac with Acronic Bootable Rescue from the same USBIII-stick
 
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