make a bootable lion installer disk from a dmg file

#MAKE A BOOTABLE LION INSTALLER DISK FROM A DMG FILE MAC OS X#
#MAKE A BOOTABLE LION INSTALLER DISK FROM A DMG FILE MAC OS#

Those of you who want a more turn-key solution should consider Lion DiskMaker, a donationware AppleScript app that will let you make a bootable DVD or thumb drive from a Lion or Mountain Lion installation program. Once it's done, eject it, label it clearly, and either use it to install Mountain Lion on a newly formatted hard drive or if you've already upgraded through the normal installer, put it away for a rainy day. It will take some time for the drive to be written. You may have to authenticate as an administrator.ġ0. Click Restore and agree to Erase the drive and replace it with the contents of InstallESD.dmg. Mount InstallESD.dmg (by double-clicking) and drag the mounted image from your desktop into the source location (Thanks, shamguy4) Drag Untitled 1 from the left column to the destination field. Drag InstallESD.dmg into the file-open window and click Open. Next, select the new partition (Untitled 1 by default). Wait as it unmounts, partitions, and remounts your disk.Ĩ. Click the Options button at the bottom-right of the partition layout.

#MAKE A BOOTABLE LION INSTALLER DISK FROM A DMG FILE MAC OS#

Choose Format > Mac OS Extended (Journaled).Ħ. With this drive selected, click the Partition tab and choose Partition Layout > 1 Partition. Drives are listed first with their partitions listed after them, each partition indented slightly.ĥ. Prepare it for use by creating a single HFS+ partition. Attach a thumb drive to your Mac that is at least 8GB in size.

Navigate to /Applications/Utilities and launch DiskUtility.Ĥ. Open a new Finder window with Command-N (File > New Finder Window). There you'll find a disk image called InstallESD.dmg.ģ. A new Finder browser window opens, showing the normally hidden material inside the installer bundle.Ģ. These instructions work to create a bootable install disk for all versions of macOS from macOS 11 Big Sur back to OS X El Capitan 10.11. Right-click (or Control-click) the installer and choose Show Package Contents from the contextual pop-up.

#MAKE A BOOTABLE LION INSTALLER DISK FROM A DMG FILE MAC OS X#

It is called Install Mac OS X Mountain Lion.ġ. Once the large multi-GB installer finishes downloading, go to your Applications folder to find the installer itself. You can use this option-click-Purchases trick to re-download any purchase, not just Mountain Lion. An 'Install' button should appear next to Mountain Lion.

Launch the App Store and option-click the Purchases tab. If not, you'll need to re-download it from the Mac App Store. If you saved a copy when you first installed Mountain Lion, great. You'll need a copy of the OS X Mountain Lion installer. This year, I update those instructions for Mountain Lion. Last year, I posted about creating a standalone Lion USB installer thumb drive.

Make a bootable lion installer disk from a dmg file