Making OS install disk

macmesser

macrumors 6502a
Original poster
Aug 13, 2012
824
64
Long Island, NY USA
How would one make an OS installation disk from an OS installer file that would work without an internet connection? I have some legacy software which I want to use on one of my Macs that requires an older OS. I tried installing on an internal HD but got an error saying the OS can't be installed under booted OS.
 

Fishrrman

macrumors P6
Feb 20, 2009
17,490
5,678
1. Connect a USB flashdrive (16gb or larger) and erase it to Mac OS extended with journaling enabled.
2. Have the OS installer of your choice in the applications folder
3. Download the appropriate version of DiskMaker X from here:
https://diskmakerx.com
4. Launch DiskMaker X and follow its simple instructions.

To boot from the flashdrive, press power on button and then IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears. Then, select the flashdrive installer with the pointer and hit return.
 
  • Like
Reactions: macmesser

macmesser

macrumors 6502a
Original poster
Aug 13, 2012
824
64
Long Island, NY USA
1. Connect a USB flashdrive (16gb or larger) and erase it to Mac OS extended with journaling enabled.
2. Have the OS installer of your choice in the applications folder
3. Download the appropriate version of DiskMaker X from here:
https://diskmakerx.com
4. Launch DiskMaker X and follow its simple instructions.

To boot from the flashdrive, press power on button and then IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears. Then, select the flashdrive installer with the pointer and hit return.
Thanks for reply. Is there a version which will make a bootable installer for Mountain Lion?
[doublepost=1550114305][/doublepost]
Thanks. Will method work for Mountain Lion? It's simple enough so I will try when I have time to experiment and post results.
 
Last edited:

DeltaMac

macrumors G3
Jul 30, 2003
9,610
2,353
Delaware
Thanks for reply. Is there a version which will make a bootable installer for Mountain Lion?
[doublepost=1550114305][/doublepost]
Thanks. Will method work for Mountain Lion?
Yes, just get the version of DiskmakerX that supports Mountain Lion. I believe that will be DiskMakerX version 3.0.4. You will probably want to use a system that is running Lion or Mountain Lion already, as that usually gives me the best results.
And, as you know, you also need the Mountain Lion installer app to make the bootable installer. :cool:
 
  • Like
Reactions: macmesser

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,404
8,990
California
  • Like
Reactions: macmesser

macmesser

macrumors 6502a
Original poster
Aug 13, 2012
824
64
Long Island, NY USA
Yes, just get the version of DiskmakerX that supports Mountain Lion. I believe that will be DiskMakerX version 3.0.4. You will probably want to use a system that is running Lion or Mountain Lion already, as that usually gives me the best results.
And, as you know, you also need the Mountain Lion installer app to make the bootable installer. :cool:
Thanks. Unfortunately I don't have a Lion or Mt. Lion system. Will have to experiment I guess.
For Mountain Lion, use THIS version of DiskMaker:
http://diskmakerx.com/downloads/DiskMakerX304.zip
Thanks! Will try it.
 

DeltaMac

macrumors G3
Jul 30, 2003
9,610
2,353
Delaware
Thanks. Unfortunately I don't have a Lion or Mt. Lion system. Will have to experiment I guess.

Thanks! Will try it.
hmm... Your signature says you have a Mac Pro running Lion.
Which Mac do you need to install Mountain Lion? Are you sure it is supported on your Mac?
 
  • Like
Reactions: macmesser

Nermal

Moderator
Staff member
Dec 7, 2002
18,698
1,186
New Zealand
If you don't want to use third-party software: If I recall correctly, Mountain Lion has a file called InstallESD.dmg inside the application, which you can burn to a DVD using Disk Utility.
 

macmesser

macrumors 6502a
Original poster
Aug 13, 2012
824
64
Long Island, NY USA
hmm... Your signature says you have a Mac Pro running Lion.
Which Mac do you need to install Mountain Lion? Are you sure it is supported on your Mac?
hmm... Your signature says you have a Mac Pro running Lion.
Which Mac do you need to install Mountain Lion? Are you sure it is supported on your Mac?
My sig is outdated and I will update. Yes, I'm sure. I have a small fleet of compatible Macs. Two '09 Mac Pros 4,1, both flashed to 5,1. One Mac Mini, pretty sure it's a '10. My main computer is cMP 5.1 running High Sierra. I would like to revert either my other cMP or the Mac mini to Mountain Lion, as this would allow mw to run my legacy programs.
 

macmesser

macrumors 6502a
Original poster
Aug 13, 2012
824
64
Long Island, NY USA
If you don't want to use third-party software: If I recall correctly, Mountain Lion has a file called InstallESD.dmg inside the application, which you can burn to a DVD using Disk Utility.
I have the full installer file. Will have to see if I can unpackaged that file from the full installer. I wonder if it will need other resources. If so, I will need to point it to them, unless this will be automatically taken care of.
[doublepost=1550198747][/doublepost]
Do you already have the full Mountain Lion (4.4 GB) installer?
Yes, I do have the full installer.