Hello everybody, I was wondering how can I determine among the modules loaded at boot which of them are really necessary and which are not, in order to reduce the boot process time and have a more "elegant" system start.

I know this theme is a little bit of complicated because it depends of the user's point of view and demand a high knowledge of which things are happening in your system but I need somewhere to start improving the performance of my debian system.

Thanks in advance for any eventual answer. =)

You can use the command lsmod to see what is used at that time and make sure those are compiled in the kernel to boot up cleaner.

With "lsmod" I get the list of modules that are actually being loaded each time my system starts. But do you know where I can get information of what is given module in order to estimate if it is crucial or not to have it loaded by the system at start up?

PD: I am also confused about something, at the moment of the start up, the kernel begins loading these modules as services right? So to improve the boot time I have to remove the modules that are not crucial for the start up and this way the kernel won't load the services they provide. Am I right or wrong?

If you need a module, it is best to compile it into the kernel. See http://www.linuxchix.org/content/cou...acking/lesson2. It will always be faster loading if the necessary modules are already a part of the kernel. For those things that are needed rarely, only run with specitic programs or tasks that are only occasionally used, one might consider that some savings would be realized, but most modules run for a purpose do not unload themselves and programmers often do not clean up. Then they are left loaded and take up unneeded space.

But considering the cost of memory, I think it is a false hope to try to save any actual cost by skimping on the kernel unless you have a need to conserve memory. You really don't end up saving much if any. So I suggest you just compile into the kernel any routines you use even just occasionally and you will be better off. Boot time for an extra megabyte is almost unmeasurable at the console.

The only caveat is that your kernel is larger and monolithic and might be more difficult to upgrade. I haven't experienced that and find the convenience of not having to call for module inserts makes most jobs easier. The monolithic nature makes module upgrades require a recompile of the entire kernel. So what? a few minutes more? Big deal.