Need help creating Big Sur installer...

[Killerbob]

I toasted my old MacBook Pro 2014, and the web-based macOS restore is not working. So, I guess I need to install the latest macOS that is compatible with that MBP, and that is Big Sur. I need Big Sur so I can install OCLP and then get Sonoma onto the MBP.

I found and installed the InstallAssistant.pkg, but for the life of me, I can't figure out how to get that installer onto a bootable USB stick. I only have Macs running Sonoma, and when I dbl. click the pkg file, it only installs a few hundred MBs of files, not the big installer that I use to create a USB Installer stick (using Terminal).

It's been a few years since I had to do this, and I am a bit lost (and annoyed).

Help...

 

[Killerbob]

Never mind... I found the Mist app, and that is a lifesaver...

 

[gank41]

I toasted my old MacBook Pro 2014, and the web-based macOS restore is not working. So, I guess I need to install the latest macOS that is compatible with that MBP, and that is Big Sur. I need Big Sur so I can install OCLP and then get Sonoma onto the MBP.

I found and installed the InstallAssistant.pkg, but for the life of me, I can't figure out how to get that installer onto a bootable USB stick. I only have Macs running Sonoma, and when I dbl. click the pkg file, it only installs a few hundred MBs of files, not the big installer that I use to create a USB Installer stick (using Terminal).

It's been a few years since I had to do this, and I am a bit lost (and annoyed).

Help...

Apple has a Support Page that lists how to create a USB installer from a Terminal Command and for each release, including Big Sur--

Create a bootable installer for macOS - Apple Support

You can use a USB flash drive or other secondary volume as a startup disk from which to install the Mac operating system. These steps are primarily for system administrators and other experienced users who are familiar with entering commands in Terminal.

support.apple.com

There's another app called DownloadFullInstaller that's similar to Mist--

GitHub - scriptingosx/DownloadFullInstaller: macOS application written in SwiftUI that downloads installer pkgs for the Install macOS Big Sur application.

macOS application written in SwiftUI that downloads installer pkgs for the Install macOS Big Sur application. - scriptingosx/DownloadFullInstaller

github.com

Mist is pretty great, though.

 

[Killerbob]

Apple has a Support Page that lists how to create a USB installer from a Terminal Command and for each release, including Big Sur--

That method requires the installer to be extracted from the downloaded InstallAssistant.pkg, and for some reason that didn’t work for me… All I got when executing the pkg file was a folder with a few files, and that obviously wasn’t enough.

 

[DeltaMac]

So, are you saying that the Mist app did not help you?

You can also download macOS installers through the OpenCore-Patcher app. That app also allows you to create a USB installer. You don't have to include the OpenCore patchers with that installer, so it can then be used as a normal system installer on any Mac that natively supports that particular version. I have made a number of different version system installers, some turn out to be less reliable, and some need more "wait time" than you might expect, particularly on older flash drives. Fastest results come with external PCIe drives (I have about 10 of those, with various combinations of multiple system installers that I try to keep up-to-date with current macOS versions.

 

[Killerbob]

The Mist app worked flawlessly…

The MacBook Pro didn’t have any macOS installed, and so I needed a stick with Big Sur for the initial installation of an OS, and then I could install OCLP and then upgrade to Sonoma.

 

[DeltaMac]

Yes, upgrading an existing system is one way to get that OCLP system installed.
You can also make a bootable installer with the OCLP installed on that installer. You can then erase, and do a clean install to Sonoma in one shot, no need to have an older system version already installed.
But, it also helps when you have another Mac to make the bootable installer.
I guess you didn't have another Mac as an option.