USB Not Bootable from Big Sur DMG

Already made two bootable macOS USB installer with Etcher and it works fine for Mojave and Catalina. However, After burning a Big Sur DMG file, the USB is not recognized when booting from Mac with Option key.

I guess it may be a problem with the bootable USB you created.
Why not create a new one with other ways/software?How about Terminal?

What image are you flashing? The best way to create a bootable USB with macOS is indeed to use the macOS installer’s createbootablemedia script.

I got two software that can help you to create a bootable macOS Big Sur USB installer again.

macOS Big Sur. I am on PC and can not use ‘createinstallmedia’ command

Hi,

Etcher writes an image 1:1 byte for byte. The DMG that you have for MacOS isn’t actually a raw disk image so writing as such isn’t going to produce a bootable image.

If your goal is to create a bootable MacOS image then Etcher isn’t the tool to use, sorry.

One of my friends successfully made a bootable macOS USB from Catalina DMG. I thought it could be capable of doing that. If not, what’s the option?

Thanks

Hi,

Sorry that you can’t use Etcher for this, maybe you can find something useful in this guide https://support.apple.com/en-vn/HT201372.