If there is one feature of OS X server that isn’t used enough it’s [NetBoot]. It’s a feature of OS X server that’s simple, powerful and built-in for free. Most of all it’s underused. Even Apple have only just started to fully embrace it’s potential after over a decade since it’s release. In my workplace it’s an invaluable tool without which hours would be lost each day. Granted that’s a fairly unique situation. Still, there are a number of uses for NetBoot which simply aren’t considered or understood.

NetBoot is very simple. Use System Image Utility to copy a bootable disc onto your server¹. Start the NetBoot service in Server Admin.

Plug any Mac it into your network with an ethernet cable and reset the PRAM to make sure the interface is set to DHCP. Hold the n key on startup to boot to that OS.

That’s it! You can further complicate matters if you wish, but you really don’t need to. NetBoot can work from a PPC server to Intel Macs or vice versa. I even run an OS 9 NetBoot image from my 10.6 Intel server.

Now, even without a hard drive installed, your MacBook can boot to a Snow Leopard installer or a full 10.6.4 OS with your own software installed. Feel free to change anything you want because when you restart it will all go back to how it was when you first booted (it’s read only).

The beauty of this is that it works with both bootable OS’ (NetBoot images) and bootable installers (NetInstall images). A company can make a digital copy of the installer disks that came with their Macs that can’t be scratched and are backed up as part of the regular server backup.

If a Mac then has an issue it can be booted to that install disk to re-install the OS, repair permissions or drives, even reset a password. Anything you can do with the install DVD you can do with a NetInstall image. The only difference is that you can do it quicker, and to multiple machines at once².

Of course, you can also have a NetBoot OS to boot to. This means you can start up to another volume to run data recovery software, disk repair software, or any number of other uses. The very process of booting to another volume is handy for troubleshooting startup issues. You can have your own software installed and even clone the OS to a local disk so all client machine start out with the same basic config.

NetBoot is very customisable, but the real value is in it’s simplicity. You can have many machines booted to a single image at once, have many images available to boot to at once, you don’t need a local drive at all to boot, and don’t need to manage the DVDs that you inevitably loose anymore. All this for 2 minutes setup and a lifetime of effortless control.

1. That will create a read-only, bootable OS in an *.nbi (NetBoot Image), stored in the directory /Library/NetBoot/NetBootSP0.
2. 10.4 with optional installs for example can install in as little as 120 seconds. That’s a full OS install in less than 2 minutes.