I'm recycling some donated computers that Goodwill here resells. Of course these have reached the end of their lifecycle so they usually only support snow leopard. The next step is trying a more recent OS.
My first step was to use the standard method to create a USB that would install LION. Createinstallmedia. Then I put it in the machine boot with the ALT key, choose the installer when the options appear. Then it boots right back ... to Snow Leopard .
So I try creating a truly bootable USB. I verify them by using System Preferences > Startup Disk to see if it appears. The easiest way I've found has been to use Disk Utility to restore a DMG image to the USB drive. If one isn't online I use the INSTALLESD.DMG from the installer.
I do this because the new installers available now also don't create a bootable disk. In addition to testing for STARTUP DISK there should be a BOOT.EFI file in the System/Library/Coreservices directory. Even then this method isn't 100% effective.
My next step would be to boot one of my known good machines into Recovery and target the USB. Coincidentally all my other machines run either Sierra, High Sierra or Big Sur. Neither is supported on the machines I'm working up.
So I'm looking for two answers
1) Why won't these techniques produce a bootable USB ?
2) Since these methods haven't worked, what will ?
[I've created a new, separate, thread since it has to do with the boot process and various computers. If this is in violation of forum guidelines please let me know.]
My first step was to use the standard method to create a USB that would install LION. Createinstallmedia. Then I put it in the machine boot with the ALT key, choose the installer when the options appear. Then it boots right back ... to Snow Leopard .
So I try creating a truly bootable USB. I verify them by using System Preferences > Startup Disk to see if it appears. The easiest way I've found has been to use Disk Utility to restore a DMG image to the USB drive. If one isn't online I use the INSTALLESD.DMG from the installer.
I do this because the new installers available now also don't create a bootable disk. In addition to testing for STARTUP DISK there should be a BOOT.EFI file in the System/Library/Coreservices directory. Even then this method isn't 100% effective.
My next step would be to boot one of my known good machines into Recovery and target the USB. Coincidentally all my other machines run either Sierra, High Sierra or Big Sur. Neither is supported on the machines I'm working up.
So I'm looking for two answers
1) Why won't these techniques produce a bootable USB ?
2) Since these methods haven't worked, what will ?
[I've created a new, separate, thread since it has to do with the boot process and various computers. If this is in violation of forum guidelines please let me know.]