Zachary Loeber

I eat complexity and am never without a meal.

Ubuntu Server 8.04 Post Install Tip #3: Blacklist Modules

2008-07-06 2 min read Linux Ubuntu Zachary Loeber

Here is another one that you may find useful to do after a default install of probably any Linux server, Disabling extra stuff from loading at startup. Ubuntu loads a ton of them and many I do not use at all. Since when do you need joystick or sound support on a server anyway? Anyways, here are some I disable and how I disable them.

IPV6 might cause you some trouble. If your router does not support IPV6 (or still only supports IPV4, which is 99% of all routers), you will have no use for IPV6. Unless you are using IPv6 it also adds an entire network stack to your running server. A stack that needs to be secured for every service. So ipv6 will be the first blacklisting it in /etc/modprobe.d/blacklist.

We may as well disable all those annoying sound modules from loading. So lets find out what sound modules should be blacklisted. I have on-board sound and I believe that the modules gets auto detected via a series of detection scripts in /etc/modprobe.d/alsa-base so I have to be a bit more specific in the blacklist. Find out how the sound modules are getting loaded. As you can see from the command below the via82xx on board sound module is getting loaded. If in doubt just blacklist ’em all.

12:59:13 shadowbox /etc/modprobe.d: lsmod | grep snd<br /> snd_via82xx 29464 0<br /> snd_ac97_codec 100260 1 snd_via82xx<br /> ac97_bus 3200 1 snd_ac97_codec<br /> snd_pcm 80388 2 snd_via82xx,snd_ac97_codec<br /> snd_timer 24324 1 snd_pcm<br /> snd_page_alloc 11528 2 snd_via82xx,snd_pcm<br /> snd_mpu401_uart 9600 1 snd_via82xx<br /> snd_rawmidi 25728 1 snd_mpu401_uart<br /> snd_seq_device 9228 1 snd_rawmidi<br /> snd 54532 7 snd_via82xx,snd_ac97_codec,snd_pcm,snd_timer,<br /> snd_mpu401_uart,snd_rawmidi,snd_seq_device<br /> gameport 16776 2 snd_via82xx,analog<br /> soundcore 8800 1 snd

Ok with this knowledge we will begin blacklisting. I’ve added a few others related to sound and joystick devices just to be all inclusive

sudo nano /etc/modprobe.d/blacklist

add the following at the bottom

# Stop ipv6 from loading
blacklist ipv6

# Stop the annoying pc speaker from beeping when local.
blacklist pcspkr

# Stop all those damn sound modules from loading.
blacklist snd
blacklist soundcore
blacklist snd_via82xx
blacklist gameport
blacklist snd_ac97_codec

Then reboot like so:

sudo reboot now

I’m sure I could shave off a few other modules like the printer port (parport_pc) and the floppy (floppy) but this generally suites my needs and is a good start.