demo-tuned

Quick demo of tuned capabilities

Tuned is a daemon that uses udev to monitor connected devices and statically and dynamically tunes system settings according to a selected profile. Tuned is distributed with a number of predefined profiles for common use cases

Notes

Question: Ever opened a case or search KBase for best practices related to performance?

• Answer: tuned
• Predefined sysctl and sysfs settings, based on best practices and real-world workloads

Tuned provides recommended configurations for common workloads

• Easy to apply
• Easy to customize
• Persists across reboots
• Installed and enabled with RHEL 7 and RHEL 8
• Available for RHEL 6 as well

Number of predefined profiles for common use cases:

• Default profiles from base package

  • balanced -- default power-saving profile. It is intended to be a compromise between performance and power consumption
  • powersave -- for maximum power saving performance
  • throughput-performance -- server profile optimized for high throughput
  • latency-performance -- server profile optimized for low latency
  • network-latency -- for low latency network tuning
  • network-throughput -- for throughput network tuning
  • virtual-guest -- based on the enterprise-storage profile that, among other tasks, decreases virtual memory swappiness and increases disk readahead values.
  • virtual-host -- based on the enterprise-storage profile that, among other tasks, decreases virtual memory swappiness, increases disk readahead values and enables a more aggressive value of dirty pages

• Additional Profiles for:

  • Atomic and OpenShift
  • Oracle (via optional repo)
  • SAP & SAP HANA included in RHEL for SAP sub
  • Via the tuned-profiles-compat package available in the Optional channel

Monitoring plug-ins

• disk -- Gets disk load (number of IO operations) per device and measurement interval.
• net -- Gets network load (number of transferred packets) per network card and measurement interval.
• load -- Gets CPU load per CPU and measurement interval.

Tuning plug-ins

• cpu -- Sets the CPU governor to the value specified by the governor parameter and dynamically changes the PM QoS CPU DMA latency according to the CPU load
• eeepc_she -- Dynamically sets the FSB speed according to the CPU load
• net -- Configures wake-on-lan to the values specified by the wake_on_lan parameter
• sysctl -- Sets various sysctl settings specified by the plugin parameters
• usb -- Sets autosuspend timeout of USB devices to the value specified by the autosuspend parameter
• vm -- Enables or disables transparent huge pages depending on the Boolean value of the transparent_hugepages parameter
• audio -- Sets the autosuspend timeout for audio codecs to the value specified by the timeout parameter
• disk -- Sets the elevator to the value specified by the elevator parameter
• mounts -- Enables or disables barriers for mounts according to the Boolean value of the disable_barriers parameter
• script -- This plugin can be used for the execution of an external script that is run when the profile is loaded or unloaded
• sysfs -- Sets various sysfs settings specified by the plugin parameters
• video -- Sets various powersave levels on video cards (currently only the Radeon cards are supported)
• bootloader -- Adds parameters to the kernel boot command line

Dynamic tuning is globally disabled in Red Hat Enterprise Linux and can be enabled by editing the /etc/tuned/tuned-main.conf file and changing the dynamic_tuning flag to 1

References and Resources

• Red Hat Documentation - RHEL 7
• Red Hat Documentation - RHEL 8
• Red Hat Documentation - RHEL 9
• Interactive Lab - TuneD