DaveWT
Well-Known Member
I think it is time to do a clean install on my iMac after years of just upgrading the macOS, leaving a lot of increasing cruft behind. I have looked at instructions for doing this, on various "trusted" web sites (iMore, MacWorld etc.) and each site gives a slightly different command to be used in Terminal to accomplish this. The instruction on the iMore site (https://www.imore.com/how-create-bootable-installer-mac-operating-system) was unique in that it says if the target drive on which you wish to do the clean install is formatted for APFS (which mine is) then the thumb drive on which you are trying to create an installer should also be formatted for APFS. None of the other sites made such a claim. So is this an absolutely necessary requirement?
I have formatted the thumb drive as APFS but when I try to run the iMore supplied command I get an error message.
"If you wish to continue type (Y) then press return: Y
APFS disks may not be used as bootable install media.
An error occurred erasing the disk."
So this states that I shouldn't be formatted for APFS in spite of iMore's instruction. Have I misread the iMore instructions? I have now reformatted the thumb drive as MacOS Extended (Journaled) and the process appears to be proceeding properly. But will this thumb drive then be able to install Catalina on a completely erased APFS drive in my iMac?
I have formatted the thumb drive as APFS but when I try to run the iMore supplied command I get an error message.
"If you wish to continue type (Y) then press return: Y
APFS disks may not be used as bootable install media.
An error occurred erasing the disk."
So this states that I shouldn't be formatted for APFS in spite of iMore's instruction. Have I misread the iMore instructions? I have now reformatted the thumb drive as MacOS Extended (Journaled) and the process appears to be proceeding properly. But will this thumb drive then be able to install Catalina on a completely erased APFS drive in my iMac?
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