It's possible to manually tune all kernel parameters and include those items in a hand created shell script. This quickly becomes cumbersome though and the tuned service can take care of this need easily. Using tuned you can tune specific kernel parameters and save that configuration as a profile. Switching between profiles is nearly instantaneous.
- [Instructor] Tuned is a service that uses U dab to monitor devices and tune system settings accordingly. Tuned uses configuration profiles for various targets and comes with several predefined profiles for cases such as, low latency, high throughput, and power saving. You can modify settings in an existing profile, make copies of profiles, and or switch between them. Normally, Tuned runs as a service, however, a new feature of Tuned and enterprise Linux seven dot two and newer, is the ability to run without being a service. There are many features missing in this mode, but it allows one to use Tuned to modify settings and then exit.
This mode is turned off by default. Tuned can modify static settings, as well as dynamic, with static settings, it mostly changes sysctl and sysfs settings, with dynamic configuration, Tuned monitors system usage and modifies the configuration based on the results. Tuned supports two types of plugins, monitoring and tuning. Monitoring plugins get information from the system. Tuning plugins modify the system configuration. Monitoring plugins currently include disk, net, and load, the data from monitoring plugins can be used for dynamic tuning, by the tuning plugins.
Tuning plugins include cpu, net, sysctl, usb, vm, audio, disk, mounts, sysfs, video and more. Tuned should be installed by default, but lets ensure this by using yum, in a terminal, type in sudo space yum space install space dash Y space Tuned and hit enter. Type in your password if prompted. (keyboard clicking) Now that we know Tuned is installed, let's start it.
Type in clear and then type in sudo space systemctl space start space Tuned and hit enter. Let's also make it persistent, type in sudo space systemctl, space enable space Tuned, and hit enter again. To get a list of all installed Tuned profiles use the Tuned dash adm command, type in sudo space tuned dash adm space list, and hit enter. To view the currently active profile, pass the active option, type in sudo space Tuned dash adm space active, and hit enter.
We can see that we're using the virtual guest profile, this was done on install. To change profiles, we'll use a profile option, let's select the desktop profile, type in sudo space Tuned dash adm space profile space desktop, and hit enter. And we can verify this by using the active option again. If you provide more than one profile as an argument, Tuned attempts to enable all settings, although there is no sanity check, if there are conflicts, the last profile loaded will override the first.
Tuned can also recommend a profile if you want, type in clear and then type in sudo space tuned dash adm space recommend, and hit enter. And we can see that it recommends the virtual guest profile instead of the desktop profile that we're in now. To disable all tuning, we'd use the off option, which we won't do at this time.
- Performance monitoring
- Gathering statistics
- Tuning the kernel with tuned
- Tuning the kernel manually
- Managing kernel modules
- Installing kernel modules from disk
- Logging system messages remotely