There are a variety of ways to automatically or semi-automatically install systems, especially Linux systems and especially over the network. People have built a whole raft of them over the years, often with relatively impressive capabilities. A number of them have significant levels of automation and control, including for things we might want like sophisticated automatic disk setup . Despite that, we're interested in approximately none of them. As a practical matter, we only want to use the standard, native install systems for whatever we're running, which in this case is the Ubuntu server installer. There are two reasons for this.

The obvious reason is that only native installers and install methods are officially supported by the Linux distribution (or whatever other free Unix we're using), and they're also the ones that are most used in practice. The native installers aren't always perfect, but other people work (often quite a lot) on making them work well, we can find plenty of people using them, and so on. If we use another installer, at the very least we're without support from the distribution. We're also likely to be off the beaten path, which means fewer people running into issues before us, fewer bug reports being filed and fixed, and so on.

The less obvious reason is that we do a certain amount of direct manual installation of servers for Ubuntu, FreeBSD, OpenBSD, and so on. The easiest way to do this is to use whatever native installer the distribution ships on their install ISO images. In the case of Ubuntu we customize this a bit, but none of our customizations are essential; we can and have installed systems straight from the main Ubuntu ISO images (and then possibly imported our customizations afterward). We could still do this even if we normally used a third party install system, but less would carry over between the two environments and we'd want to learn and stay familiar with both of them.

These issues aren't absolute blocks on using a third party installer system; we could deal with both of them. But we'd want to be getting something important from such a system, something that was enough of a gain to be worth the extra costs. I can think of situations which would be worth it but they haven't come up so far (at our modest scale and with only Ubuntu really in the picture for semi-automated installs, network installs, and so on).

(This is related to why it took us a relatively long time to build up a network install system, cf . There are specialized automated network install systems for Linux, but they run into this third party issue. Our current network install system for Ubuntu uses our Ubuntu ISO images that we also use for local installs, and that's a feature even though it creates complications .)