tech log on gentoo, linux, and random stuff

the whereabouts of kernel module configuration

leave a comment »

The salient point: just play with files inside /etc/modprobe.d/, as everything else is meant for backward compatibility.

Well this probably happens only to a dated gentoo installation where old conf files get orphaned. I was about to set some kernel module autoloading parameters, and was a bit confused seeing this:

$ ls -lad /etc/mod*
-rw-r--r-- 1 root root 3587 May  2  2008 /etc/modprobe.conf
drwxr-xr-x 2 root root  208 Mar 14 19:50 /etc/modprobe.d/
-rw-r--r-- 1 root root 2955 Dec  6  2007 /etc/modules.conf
drwxr-xr-x 2 root root   72 Jun  5  2008 /etc/modules.d/

The .conf files refer to two scripts, modules-update and update-modules, and the former doesn’t even exist. A man of the latter, however, clarifies everything. Here’s an excerpt from UPDATE-MODULES(8)

       update-modules is a simple tool to manage the module config files found
       in the /etc/ directory.

       The old Linux module utilities use a single file for all their configu-
       ration.  This makes it difficult for packages to dynamically add infor-
       mation about their own modules.

       update-modules makes the dynamic addition of information easier by gen-
       erating  the  single  configuration file from the many files located in
       /etc/modules.d/.  All files in that directory are assembled together to
       form /etc/modules.conf.

       Newer Linux module utilities include support automatically for a direc-
       tory of configuration files in /etc/modprobe.d/.  However, to  maintain
       backwards  compatibility with packages that do not yet support this, we
       still need to assemble the contents of  /etc/modules.d/  and  /etc/mod-
       probe.d/  and produce the corresponding /etc/modules.conf and /etc/mod-

       Also, when  requested,  it  is  also  possible  to  generate  /etc/mod-

Written by zsh

March 15, 2009 at 7:25 am

Posted in /etc, gentoo

Tagged with , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: