What hotplug does (in Gentoo it's called coldplug) is to detect your hardware and cause a number of modules to be loaded. Modules are part of the kernel, but instead of being compiled in, they can be loaded to a running kernel or not as need be. This means that the kernel takes less memory, because on a general purpose distro, loads of modules have to be available to cover a range of hardware that the system may encounter. In Gentoo, Hotplug then controls the reaction to things you might plug in AFTER the system has booted (USB keys, etc). When you stop Hotplug in other system, these functions still work. So Hotplug comes in two sections, if you like, which is why Gentoo calls one of them Coldplug!

The consequence of disabling Hotplug is that you have to tell your distro which modules to load. otherwise some of your hardware won't work.

In Gentoo there is a file at /etc/modules.autoload.d/kernel-2.6, and in PCLinuxOS and Mandrake/Mandriva it is at /etc/modprobe.preload. This lists the modules that the system must load. Other distros will have to have a similar file, you'll have to find it. How do you find out what modules you need?

Well you open a terminal AS ROOT, and issue the command: "lsmod"

What you get, is a list of modules loaded by hotplug. Before stopping Hotplug, you need to copy these module names, IN REVERSE ORDER, to the file I mentioned above. Only the module name, nothing else. Modules which have a further list of modules further along their line, do not need to be added specifically, as loading any of the modules in the list will cause them to load anyway, but there is no harm in you keeping them in. You may even notice some that clearly refer to hardware you don't have (eg with sata in the name) as Hotplug does tend to go too far. You could try leaving those out.

To actually stop hotplug running in Mandr*** or PCLinuxOS, you have to run the M/P Control Centre > System > Configure System Services then you just find Hotplug in the list and uncheck it so it doesn't start on the next boot. In Gentoo you have to run this line from a console as root:

If you are using another distro, you'll have to find out for yourself how to stop hotplug at startup. But of course, once you know what modules are needed, why waste time whilst a program searches them out every time you boot?

An embedded floppy distro.

Can't be...
Floppy distros are slow on boot..

I have found arch to be the quickest so far.

Gentoo or *BSD, since fbsd has screwed it up with the beastie menu. Out of *BSD, NetBSD is probably the fastest.

actually I have found Gentoo to be slower to boot up...

If you dont add any additonial services, Gentoo is faster than Arch, even if Gentoo is crap.

I once timed my old slack 9.1 box to under 16 seconds from power on to command line.

But there is one thing I'd like to point out for this thread.

We are running LINUX here! Who cares about boot times when you don't need to reboot (often) in the first place.

Currently my slack 10.1 desktop takes an annoying amount of time to boot... but I don't care, its uptime is 47 days.

Gentoo's init was not designed to be fast. It was designed for ease of use. It's more than fast enough, but it won't ever boot as fast as some other distros. When I play around with rolling my own linux, I steal Gentoo's init model and config files because it is so easy to administer.

With no hotplug, no ldconfig, a slim kernel and heavy script hacking I can get Slackware to boot from lilo to login prompt on a laptop in about 15-20 seconds, and created a run level to use it while I'm on battery. The lead developer on a well known Slack based distro project got it to boot at a timed 16 seconds. Any distro that uses BSD style init should be able to achieve these times if you're willing to play around with and re-write rc.* files.

Im a huge fan of the Gentoo Init scripts, very easy to use. Only decent thing I can say about it.