Install OS X over the network

This service was stopped at the end of 2018. From 2019 on users have to use the Recovery partition to re-install macOS, see for details.

The information below is kept for historic reference only.

Installation of  macOS is possible over the network from the NetInstall server - without the need to create any local installation volume. We provide NetInstall images for the supported version of Mac OS X, except for the .0 versions. Together with the operating system we also install the OCS Inventory Agent, see

Before starting the installation, it is recommended that you:

  • check your latest backup,
  • verify and if needed repair your disk using the 'Disk Utility'.

In most places, NetInstall will not work over Wifi (Airport). To avoid potential complications, it is recommended to turn off the Airport interface before doing a NetInstall.

To use the NetInstall service, connect your Mac to the CERN network, start the 'System Preferences' and select 'Startup Disk'. After a few seconds you should see the icon of the NetInstall image, as in the screenshot below. Select the icon corresponding to your image, and click the 'Restart…' button to restart your Mac.

When the Mac boots it will download and start the installer, and you will see the usual Installer interface. Select the target disk and make the package selection according to your preferences. It is highly recommended not to disable the 'Combo Updater' that is enabled in some of the install images.

If you do not see any NetInstall image in the list of proposed systems, you should check:

  • that you have a proper network connection. This service is not supposed to work via wireless connections, or outside of CERN;
  • that your Mac does work with the provided system versions. Non-Intel Macs do not work with 10.6 or newer, and will not show the NetInstall images.

If you do have a proper network connection and your Mac is supposed to work with one of the provided images, but you still don't get any of the images, please contact the ServiceDesk, describe the problem and provide the hostname and IP# of the Mac, as well as the 'Model Identifier' according to the 'System Information' app.