Network Booting in OS X

I created a NetBoot service on my Mac Mini which is running Leopard Server. This is great to have because it allows me to boot any Macintosh computer over the network. For instance, let’s assume that your hard drive crashed on your computer, or you need to recover data, or you need to repair the filesystem. There are several ways you can do that. You can boot off a OS X Install CD. You can configure the computer to act in Target Mode, or you can boot off an external drive. In many cases, if you need to repair a filesystem, the application or method you are using will require exclusive access to that disk or volume. You can not unmount the disk that you booted up from. Simply won’t happen.
I like having options. Even though I have my boot volumes mirrored with a dark clone, I created a network bootable operating system that has all of my data recovery tools, volume and disk repair utilities, as well as most of the typical applications I will normally use to get through the day.

Let me explain. Assume my hard drive crashed. I need to get it recovered. This could be a long process. I simply reboot the computer while holding the ‘N’ key (for Network) and it will go out and boot up an remote disk image (operating system) over the network. One the system comes up, I will be presented with a login screen. Since my home directory is not local on this computer, and the fact that I am running Open Directory, I log in as normal with my username and password. Once I am authenticated, my home directory automounts from the server and I have access to all of my data. Since the network boot image contains all of my recovery applications, I can get those going on my local hard drive, which could take a while. In addition, I have all the applications I need to do my normal work, while I’m repairing this local disk. Remember, I am booted up over the network the whole time this is happening.

Once I am finished recovering my filesystem, or data, I can simply save what ever I am working on, as normal in my home directory and reboot off the local disk, rather than the network.

I also created a NetInstall image of Leopard 10.5 which will allow me to boot a computer up over the Network and rather than being presented a full blown operating system with applications, I am simply provided the installation DVD. Just as if I booted the computer up with a Install DVD to install the OS. This is nice because now I can put the DVD away and not have to carry it around or worry about it getting scratched every time I take it out of its case.