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The drill for clean-installing Mojave PB from flash stick?

blakespot

blakespot

Administrator
Original poster
Jun 4, 2000
1,373
167
Alexandria, VA
Hey folks, I'm on vacation at the beach and wanted to play around with Mojave on my mid-2012 Core i7 MBAir (it's the oldest supported MBAir on the Mojave compatibility list). This is not my main system and I've had some filesystem corruption appear in the past 6 months -- huge #s of garbled-named folders appearing in home dir, etc. so I want to format and do a clean install on this Mac.

Can someone point me to the drill to get Mojave PB onto an external unit (which will be a SD card with SD car reader via USB in my case) and able to boot for fresh install (assuming this drill for Mojave has been worked out by now). Also, how large an SD card is needed for this? Thanks.



bp
 
If you mean using the SD card as the installer. Its easy.
Download the Mojave installer just as normal.

You need to format the SD card to macOS Journaled, and have it set to a GUID partition table. Name it "Untitled" (Without the ") while you are at it.

Then you open the terminal and paste this command:
sudo /Applications/Install\ macOS\ 10.14\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

Enter your password and hit return. Then you have a bootable installer.
 
Lunder89 said:
If you mean using the SD card as the installer. Its easy.
Download the Mojave installer just as normal.

You need to format the SD card to macOS Journaled, and have it set to a GUID partition table. Name it "Untitled" (Without the ") while you are at it.

Then you open the terminal and paste this command:
sudo /Applications/Install\ macOS\ 10.14\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

Enter your password and hit return. Then you have a bootable installer.
Click to expand...
Great. Any idea how big a volume is needed? I'm not in a position to download it before I get to a shop where I can pick up an SD card. Thanks.


bp
 
Thanks!

Hmm, macOS High Sierra is not recognizing a 64GB Lexar stick, an 8GB stick, or my ext SD card reader with any of the three SD's I have here, 32GB, 8GB, 4GB. One other stick here prompts for Initializtion, but once I click Init, nothing happens and Disk Utility reports no attached device. Not sure what's going on. mid-2012 MBAir. Hmmm.


bp
 
Lunder89 said:
If you mean using the SD card as the installer. Its easy.
Download the Mojave installer just as normal.

You need to format the SD card to macOS Journaled, and have it set to a GUID partition table. Name it "Untitled" (Without the ") while you are at it.

Then you open the terminal and paste this command:
sudo /Applications/Install\ macOS\ 10.14\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled

Enter your password and hit return. Then you have a bootable installer.
Click to expand...

I am having a similar problem. The Terminal churns out the error:

sudo /Applications/Install\ macOS\ 10.14\ Beta.app/Contents/Resources/createinstallmedia: command not found
 
Lunder89 said:
Is the installer named differently than "Install macOS 10.14 Beta"?
Click to expand...

They used the name and called "Install macOS Mojave Beta" this year.

robertcoogan said:
I am having a similar problem. The Terminal churns out the error:

sudo /Applications/Install\ macOS\ 10.14\ Beta.app/Contents/Resources/createinstallmedia: command not found
Click to expand...
The command you need is

sudo /Applications/Install\ macOS\ Mojave\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled/
 
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I am running the developer preview and not the public one. For some reason my filename was a little different.
 
I got this working (figured out the file name diff along the way), booted off flash stick, wiped SSD with Disk Util, installed. After the progress bar ended it seemed to reboot and I landed on a solid white screen which sat for hours. Rebooted and same white screen. Started over with install, same white screen. Before wiping SSD again I noted in DU that system disk had about 11GB used.

This is a supported Mac. Mid-2012 MBAir with 8GB RAM and i7.

So, machine wiped, can’t get new OS working. That leaves me in not a good place, sadly.



bp
 
If you show all devices in Disk Utility, you should be able to remove all partitions. That can sometimes solve it.
 
It sounds like it can't boot correctly. Maybe the partition table is screwed.
I assume the Mac works fine on High Sierra? (Or whatever OS it was running before)
Since you can boot from an external source the Mac should be fine.

Have you tried running First Aid on either the partition or the harddrive?
 
OP wrote:
"So, machine wiped, can’t get new OS working. That leaves me in not a good place, sadly."

This is why you don't install public or developer betas onto your "main computer drive".
You install them onto an EXTERNAL drive that you use for testing purposes.

And it's why you create a FULLY BOOTABLE CLONED BACKUP of your internal drive (existing working OS) as well, as "insurance" against the new OS hosing something on your main drive.

Go forth from this day and learn -- a sadder but wiser man.
 
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