Memory efficient Ubuntu VMs
coderwall.comHow much ram do you win, blacklisting those modules ?
All the kernel modules of my desktop sum a few KB. Only in 1 system I see "nvidia" is a big module, but it doesn't use to be loaded in virtual machines.
About the blacklisting method... I use to never touch the distribution files inside /etc/modprobe.d (to ease upgrades, differences across hosts, etc).
I think it could be better to use something like /etc/modprobe.d/local.conf or hostname.conf
And note, that the "blacklist" directive, by side effects, may avoid module autoloading at boot time, but the real way to disable a module (forever) is to use this instead of "blacklist":
install modname /bin/true
I did expect to see more tips about "userspace" configurations, where it's more easy to win MB instead of KB.
At kernel level... after change the kernel for one more light, and tune which modules are loaded... if we go for details... still you could see which params are available for loaded modules (some params may affect ram usage) and which sysctl values we can tune in the kernel (buffers, limits, etc) to affect ram usage.
Modules are loaded as they are needed. I think it's cleaner to configure your VM to _not_ have a sound card, rather than blacklisting all those snd* modules.
It would be really good to see a comparison between this, and re-using the Ubuntu Cloud images, which also provide easier initialization.
http://ubuntu-smoser.blogspot.co.uk/2013/02/using-ubuntu-clo...
Great idea! I personally haven't had any experience with the cloud images so far but now that I looked at them I really like your idea. +1
Wouldnt removing modules affect performance because some modules might be loaded for performance or memory purposes. Can there be adverse effects as well of doing this. If lightweight is only need, why not use the lightweight distributions like Tinycore linux.
I personally haven't had significant performance regressions. I tend to disable only the modules that I am sure are not going to be necessary.
Also, Tinycore linux might be great but I would like to use Ubuntu for convenience and keep my existing additional scripts and provisioning profiles compatible.
I'll have a look at Tinycore Linux though, thanks for mentioning.
I tend to use base debian for VMs. It's much smaller than base Ubuntu from both a kernel and userspace perspective.
I use Ubuntu for convenience and because that's the distro that I am the most familiar with. I know that Ubuntu is a Debian derivative but I tend to use Ubuntu because of the wide range of community resources.
Great tips! Thanks! :)