Creating a Bootable USB Installer for macOS Catalina

[Rod]

So now that the public release (plus updates) of Catalina is here and currently running on my MBP I tackled the process again on my wife's 2018 MBPr and all went without a hitch I'm pleased to report.
I did download the installer again from the Software Update site as my saved installer was prior to the supplemental updates.

Now I wanted to create a Bootable USB Installer for Catalina. I checked the Diskmaker X site and found that although still under development there is a Diskmaker X 9 version which should be capable of the task according to the developer. He does warn that the app needs to be given System Accessibility in Security and Privacy preferences.
Having followed the instructions I attempted to run the app but for some reason despite a number of attempts it could not see the USB drive plugged into my MBP. This was a blank 32Gb USB thumb drive formatted as Macintosh OS Extended (Journaled).

Not to be daunted I though I would use Terminal instead. I found the appropriate sudo command at OSX Daily and tried that but Terminal refused to recognise the command despite careful cutting and pasting with the name of the USB drive inserted where instructed.

About to give up at this point I read a couple of other unhelpful hits on the topic until I came to this one; How to create a bootable macOS Catalina installer drive | Macworld
This just seemed too easy. Download "Instal Disk Creator"(Free) and run it according to it's simple, intuitive instructions and "Bob's your Uncle"!
No System Access settings, just pick the source and the destination and click Create Installer. Thats it!
I have booted from the USB and all seems as it should but I cannot test the macOS installer as I only have the one device. Disk Utility does work and as expected shows two Macintosh HD's.

Someone might like to give this a try assuming they have backups and are not using their primary device. Until then I can only assume it works until proven otherwise.

 

[ferrarr]

I always use the Apple specified method, How to create a bootable installer for macOS - Apple Support.

 

[Rod]

Yes Bob, the "createinstallmedia" command was the one I used. Have you tried it in Catalina because I gave it a good shot without success?

 

[chscag]

I have to agree with Rod. I've used the Install Disk Creator.app before and it's much easier and less prone to terminal errors than the Apple method.

 

[Rod]

Certainly worked for this old fool, I hadn't heard of this app before although I have looked at Macdaddy Software in the past.

 

[krs]

I have used Disk Creator for all my USB installers and that worked fine for the ones I have actually used.

I passed on DiskMaker X when to use it I was asked to log in again as an admin - too much of a hassle. Never tried the terminal approach.

 

[ferrarr]

Yes Bob, the "createinstallmedia" command was the one I used. Have you tried it in Catalina because I gave it a good shot without success?

Yes, I upgraded to Catalina, then made the installer using the Apple “method”. I haven’t tried it with my clean Catalina install yet. Maybe I will try it this weekend?

- - - Updated - - -

I have used Disk Creator for all my USB installers and that worked fine for the ones I have actually used.

I passed on DiskMaker X when to use it I was asked to log in again as an admin - too much of a hassle. Never tried the terminal approach.

Same with the Apple recommended Terminal method, that you need to be logged in as an administrator.

 

[Rod]

Maybe I made an error although I was pretty sure I got it right. Also I checked the sudo command I had against the one in your link and they were identical. If nothing else this perhaps illustrates the likelihood of users making errors with Terminal which is a good recommendation for a simple app like Install Disk Creator.


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[Slydude]

I made a bootable Catalina installer a few days ago using the create install media command outlined here.

I made that one as a workaround for the fact that even when I use CCC I can't seem to get a clone that shows when I boot using the option key. I've had the same issue with Mojave for a while. In the process of I've accidentally erased both my Mojave install and almost 4 TB of data. Yikes!!!

Note: The accidental erasures were not due to the Terminal commands in that article. I pasted those in carefully. I created those disasters by not paying close enough attention using Disk Utility.

Note 2: I don't think the problems with the clones are due to CCC. The clones show in the startup preference pane but not when I boot with the Option key down.

 

[ferrarr]

Maybe I made an error although I was pretty sure I got it right. Also I checked the sudo command I had against the one in your link and they were identical. If nothing else this perhaps illustrates the likelihood of users making errors with Terminal which is a good recommendation for a simple app like Install Disk Creator.


Sent from my iPhone using Mac-Forums

Did you do a clean install of Catalina? Or did you do an upgrade over a previous OS version? If you did a clean install, that may be why it doesn't work?

 

[chscag]

Hey Sly:

I made that one as a workaround for the fact that even when I use CCC I can't seem to get a clone that shows when I boot using the option key. I've had the same issue with Mojave for a while. In the process of I've accidentally erased both my Mojave install and almost 4 TB of data. Yikes!!!

I just read this and wondered if CCC will notify me when I boot the clone using the Option key. And yes, it very clearly warns me that I'm booted from the clone and it then asks me if I want suspend the task. If I continue, it offers to lead me by the hand to recover.

I'm not sure how you accidentally erased your Mojave install and other data? Are you using the latest version of CCC?

 

[Lifeisabeach]

DosDude has free utilities for creating a bootable installer. These will even download the installer for you direct from Apple. His Catalina one does work.
dosdude1's Personal Web Server - Software

TinkerTool System (not to be confused with plain old TinkerTool) was just updated with the ability to do the same. With this, you can actually specify the exact version of the installer you want (say, 10.14.3 vs 10.14.6). I haven't tried it myself yet... this feature just came a couple days ago. It's not a free app, but is a rather excellent utility. Some of its features are found in Onyx, but it has a handful of other handy tools available.
TinkerTool System 6: Description

 

[Slydude]

Hey Sly:



I just read this and wondered if CCC will notify me when I boot the clone using the Option key. And yes, it very clearly warns me that I'm booted from the clone and it then asks me if I want suspend the task. If I continue, it offers to lead me by the hand to recover.

I'm not sure how you accidentally erased your Mojave install and other data? Are you using the latest version of CCC?

I'm not sure how a CCC clone behaves when one tries to boot using the Option key method. That's what I was trying to correct.

As for the loss of data and loss of my Mojave partition, that was not the fault of CCC. My thought was to split my Mojave drive into two partitions and place a clean Catalina installation on the blank area I created on that drive. In essence, the drive would have had a Mojave clone and Catalina clone on the same drive. I've done that many times in other OS versions with no issues. I created the necessary space using Disk Utility and must have gotten a bit careless and selected the wrong drive. Net result, -- Mojave clone erased entirely.

When I tried the Catalina install I had made on that external drive it did not boot when the option key was pressed so I decided to try again in case I had skipped a step. This time I accidentally selected a different drive with quite a bit of data and erased that drive as well. Let's just say I had a very bad day that day.

These losses were not due to errors/bugs in Disk Utility or Carbon Copy Cloner. The mistakes were mine and mine alone. I was doing several other tasks during this time and not paying enough attention.

That's probably going to cost me a hat or two.

 

[chscag]

Let's just say I had a very bad day that day.

Wow.... we are going to have to take a closer look at your hat size. Looks like it's shrinking.

 

[Rod]

Did you do a clean install of Catalina? Or did you do an upgrade over a previous OS version? If you did a clean install, that may be why it doesn't work?

Nope, I was not too sure about this OS so I did an upgrade over the Mojave OS.

 

[Rod]

I just read this and wondered if CCC will notify me when I boot the clone using the Option key. And yes, it very clearly warns me that I'm booted from the clone and it then asks me if I want suspend the task. If I continue, it offers to lead me by the hand to recover.

I get the same result as above.

 

[Slydude]

Wow.... we are going to have to take a closer look at your hat size. Looks like it's shrinking.

Another day like that and you'll be sending dunce caps rather than cowboy hats.