Installing Lion and Mountain Lion instead of “Imaging”
Now that you can create an Installer package to install Lion or Mountain Lion, you have the possibility of using this package instead of an “image” to initially setup/configure a machine.
This may not be initially obvious.
If you’ve used InstaDMG or Apple’s System Image Utility to build a deployment image, you might notice that the components you use are very similar to the components you use to create a Lion or Mountain Lion installer package. Those components are:
- OS X installation media (usually an InstallESD.dmg)
- One or more additional packages to install after the OS is installed.
The difference is that InstaDMG “compiles” those components into a disk image that you “restore” to a target volume. System Image Utility can do that as well, or it can create a NetInstall workflow that just installs the components in order.
An advantage of the “compiled” disk image approach is speed. It’s much faster to restore a disk image to a target volume than it is to install the components seperately.
But there are advantages to the “install the components” approach as well:
- You can upgrade or reinstall OS X on a current boot volume without affecting user data. “Imaging” requires erasing the target first.
- Installing Lion or Mountain Lion causes the appropriate Recovery HD to be created automatically. If you use an imaging approach, you have create the Recovery HD separately; either by capturing and deploying an image of the Recovery HD, or using another scripted process to create it.
- InstaDMG and SIU generally limit you to building an image on the same OS; in other words, you can only build Mountain Lion images on a Mountain Lion machine, and Lion images on a Lion machine. createOSXinstallPkg allows you to create Lion and Mountain Lion installers on Snow Leopard, Lion, and Mountain Lion.
It’s possible to use DeployStudio to install Lion or Mountain Lion on a target volume using a package created by createOSXinstallPkg. You can upgrade an existing volume, or erase and install to an empty disk. Rich Trouton has documented these options:Deployment, Lion, Mountain Lion, OS X, Packaging