How to make a bootable Mojava on USB drive in Catalina ?

[bo-waleed]

I know about the old way when you have to open the installer then restore disk image to USB.

But in Catalina the installer doesn't open at all.

I already have Mojava 14.6 installer downloaded from App Store

 

[DeltaMac]

Correct. The Mojave installer won't open when you are booted to Catalina.
But, if you are making a bootable installer (USB flash drive?), there's no reason to open the Mojave installer app. Just make the bootable installer. Apple has all the steps here: https://support.apple.com/en-us/HT201372
Or, if you struggle with interpreting how to setup the command in the terminal, here's some detailed steps to follow to make that work.

Make macOS installer bootable on flash drive:
Insert your USB flash drive (use a 16GB flash drive for this). Erase that thumb drive, using your Disk Utility. Make sure it is formatted Mac OS Extended (journaled), and the partition Map is "GUID"

The Mojave installer app (Install macOS Mojave) should be in your Applications folder.

Right click on that installer app, and choose "Show Package Contents". Open the Library, then open the "Resources" folder. Leave that alone for a moment...

Launch your Terminal app, then type sudo, and add a single space.

From the Resources folder that you left open, drag the file "createinstallmedia" and drop it on your terminal window. You will see the full path to that file appear next to sudo.

Next, type --volume, and add one space to that. (notice there are TWO dashes, not just one)

Now, find the icon for your flash drive (the one you just erased. Should be on your desktop somewhere). Drag that icon into the terminal window. You will see that disk, with its path, added to the line you have been typing.

AND, press enter. You will be asked to enter your admin password. Do that, you will NOT see what you type (it's a security feature, just type your password, then press enter. It will work.

Finally, the terminal will ask you to press "y" to start the command that you just typed, so type Y, and press enter.

Then, you will see some numbers appear, showing the progress of the command. This can take a while on some thumb drives, myabe 20 minutes, but it will eventually get to 100%, then do a few things to complete the installer and make it bootable. And, it's ready to go!

 

[deviant]

just download https://macdaddy.io/install-disk-creator/ , insert the USB key and click 1 button

 

[MCEStaff]

oops. wrong thread