There are actually 2 definitions for the term 'boot' disk in linux. In the days before motherboards allowed people to 'boot' a system with a cdrom, there was a way to install linux, by making up a boot disk using a dos based utility called rawrite. (Think i spelled it correct) . It was located in a directory called something like dosutils on the install cd rom. There was also a directory with iso images of 1.44 meg floppys, that this prg. could use to build an install froppy to start the install process to a point that it could be continued from ram and the install cd. After the time when cd devices could boot a system, the process was rarely used.
The type of disk I was referring to is kind of like the 'emergency startup disk' that windows urges you to create so you can boot a system to dos, if the traditional method doesn't work. The main difference here is that the linux start disk, generally doesn't leave you stuck in a console 'dos like' environment. The startup disk, takes into consideration where you have placed your / (root), /boot, and other partitions and boots your system pretty much like a normal boot, leaving you where you would normally be (usually runlevel 5 graphical gui, if that was your choice for system startup) The other level would have been level 3, a text console.
It is good to have emergency startup disks for all the systems you have on your drives if possible. In theory you could create a linux install with 2 parts. one / (Root) , and the other linux swap. The idea of multiple partitions gives you latitude to adjust your system later. I do generally create a separate /boot partition, for the linux kernal. You see in the old days, there was a hardware limitation, that would not let you start up an operating system, if the startup was placed too far inside a drive. ie too many cylinders in. I think lilo has pretty much eliminated that problem, but a separate /boot partition still isn't a bad idea. Make it an early primary one. The rest of it, if I'm not mistaken, could all be non primary partitions in your linux install. During your install, make the suggested linux boot floppy, when it asks you. That way if you install another OS, or something else messes up lilo, or grub, you can probably start your OS up, from floppy. All though there are commercial partition products out there, I have never used one to change a partition type. Generally when they asked you where you wanted to install the boot loader and offered you a separate partition to put it on, it's because nobody wants to catch the grief, if someone puts lilo or grub on their MBR, and wipes out their access to the data on there other OSes. I've seen people have other boot managers put on their drives for hardware compatability, not even know that they were there, then mess with the MBR for any number of reasons, even the old fdisk/mbr dos command and lose all access to their hard drives. Since I know the structure of my drives, and OSes, I put the boot manager in the mbr of the first hard drive. But then again, I am not familiar with the NT, 2000, XP or XOSL os requirements. Therefore I always caution users to back up all their important data, since messing with Master Boot Records, partitioning, and formatting can be the most destructive things you can do to a drive. Does this sort of clear things up any?
