TuneD

Recently I had someone 'in the field' make a comment that one of our servers was not optimized to send video.

I reported this comment back to the Principal Engineer, who informed me that he had installed a package called TuneD on the server, which - depending on how it is configured of course - handles the automatic activation of certain "profiles"; each having a set of optimization parameters.

I looked into this. Sure enough, I found 2 directories; /etc/tuned and /usr/lib/tuned.

The /etc/tuned/ directory contains the main, or high level, configuration file (tuned.conf).

In the /usr/lib/tuned directory contains a list of individual system profiles. On the system I looked at, it appeared that the default profiles (provided by the tuned packagers) were included - which is probably a good thing if you then proceed to examine each of these profiles.

Inside /usr/lib/tuned, a file exists for each individual profile. So for example, in a "balanced" profile, if one were to peek inside of it with an editor (it is a text file), one would see a number of sysctl kernel parameters with specific values that get set when that profile is activated.

The tuned package uses a command line administrative tool called "tuned-adm" to get things done. It is quite simple, actually. Arguments include "off" (disable), "list" (list profiles), "active" (show the active profile"), and even "recommended" to show the recommended profile. If the system is not configured to automatically activate a profile, or a particular profile happens to be excluded due to policy, what is recommended might not be what happens to be active!

You can also create or modify profiles with the tuned-adm tool.

A useful link to get acquainted with the tool can be found at:

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Power_Management_Guide/tuned-adm.html