How small can you make Open Solaris - Part 1
Solaris started its life as operating system for workstations and then progressed to servers. It has always been an operating system dominated by features, showing Sun's R&D capability. This is great if you are installing a server or a desktop, but has far too many features for building an appliance. Luckily the installing comes with some reduced installation clusters which tries to bring the installation down to the bare minimum. Unfortunately the last time I looked the smallest install was still several hundred megabytes. Linux on the other hand has had a project going for while now called "Damn Small Linux", which strips Linux down to around 50 megabytes. This is a perfect base to start building an appliance, build your own distro, or strip the kernel down further for an embedded device.
Can Solaris become as small as "Damn Small Linux". The answer is a resounding yes (and probably smaller). Lets investigate how this can be done. The first thing to do is to state the goal, which is to be able to successfully boot into a shell and execute a simple command such as 'ls'. The logical place to start is with the smallest running version of Solaris supplied by Sun. If you have a x86 grub version of Solaris you will find a 52 megabyte file in your /boot directory called x86.miniroot-safe. This file is a gzipped UFS image that is booted when you select "Solaris failsafe" from the grub menu. Using it to boot to single user mode will mount the root filesystem and give you a root shell. It also contains the code to start a Solaris installation.
Now we have found an ideal candidate, lets start ripping it apart. The first step is to copy it (as you may need it if you break something), and setup new menu option in grub.