Bootable Catalina usb installer

tywebb13

macrumors 68020
Original poster
Apr 21, 2012
2,493
903
To make the bootable usb installer for the first beta of Catalina, once downloaded to the Applications folder format a 16GB USB as HFS+ Journaled, call it Untitled and run this command in Terminal:

sudo /Applications/Install\ macOS\ 10.15\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

You can then boot up with option key and select the bootable usb.

It is likely the command will change when the second beta comes, maybe to

sudo /Applications/Install\ macOS\ Catalina\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

with "10.15" replaced by "Catalina".

When public release happens, the command becomes

sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled
 
Last edited:

zorinlynx

macrumors 603
May 31, 2007
6,087
8,678
Florida, USA
I am relieved to know this is still possible. Every OS release is suspenseful; "will they take this away?"

When you have to upgrade dozens of Macs this is practically a must.
 
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toru173

macrumors 6502
Apr 5, 2007
303
126
I can confirm this works as expected and creates a valid installer. It briefly flashed up a screen reminiscent of the FileVault password recovery utility, then displayed the familiar installer
 
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br0adband

macrumors 6502a
Aug 29, 2006
933
69
Now of course for those of us using other methods, I'm on the lookout for a bootable ISO once again. ;) Will have to see if the old instructions to convert the installer app are still applicable but I'm gonna bet some changes have been made yet once again, we'll find out soon enough.
 
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tywebb13

macrumors 68020
Original poster
Apr 21, 2012
2,493
903
It is likely the command will change when the second beta comes, maybe to

sudo /Applications/Install\ macOS\ Catalina\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

with "10.15" replaced by "Catalina".
My prediction about the changed command has come true with beta 2 now.

The reason I fairly confidently made that prediction is that this has become quite a regular thing going from beta 1 to beta 2 for several versions now.

The reason is beta 1 literally doesn’t have a name until the keynote at wwdc, but they want all the betas ready anyway for that event. So beta 1 is nameless. But by the time beta 2 comes it has a name.
 
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amaze1499

macrumors 6502
Oct 16, 2014
262
175
Where do you redownload the installer? Mine was deleted automatically after upgrading. Any ideas?
 

bogdanw

macrumors 65816
Mar 10, 2009
1,050
532
What are the requirements to download, because when clicking on the Download button I get " This version of macOS 10.15 can't be installed on this machine"
Once it will be released, Here Are All the Macs Compatible With macOS Catalina https://www.macrumors.com/2019/06/03/macos-catalina-compatibility/
Now it's in beta and you have to enroll into the beta program to download it
https://beta.apple.com/sp/betaprogram/
or
https://forums.macrumors.com/thread...lina-and-mojave-no-apple-id-required.2187881/
 
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Super Spartan

macrumors 6502a
Mar 10, 2018
538
237
Dubai
What could be the reason that when I boot up with the option key, then hit Install macOS Catalina from the USB Flash Drive by clicking that little arrow, it just starts internet recovery? Does that mean I created the USB Installer incorrectly?
 

camelia

macrumors 6502
Apr 3, 2015
381
44
Mexico City
To make the bootable usb installer for the first beta of Catalina, once downloaded to the Applications folder format a 16GB USB as HFS+ Journaled, call it Untitled and run this command in Terminal:

sudo /Applications/Install\ macOS\ 10.15\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

You can then boot up with option key and select the bootable usb.

It is likely the command will change when the second beta comes, maybe to

sudo /Applications/Install\ macOS\ Catalina\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

with "10.15" replaced by "Catalina".

When public release happens, the command becomes

sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled
Thank you!

Camelia
 
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