Chapter 4. tuned and tuned-adm
This chapter covers using the tuned daemon for tuning system settings in virtualized environments.
tuned is a tuning profile delivery mechanism that adapts Red Hat Enterprise Linux for certain workload characteristics, such as requirements for CPU-intensive tasks, or storage/network throughput responsiveness. It provides a number of tuning profiles that are pre-configured to enhance performance and reduce power consumption in a number of specific use cases. Edit these profiles or create new profiles to create performance solutions tailored to your environment.
The virtualization-related profiles provided as part of tuned include:
- Based on the
virtual-guestalso decreases the swappiness of virtual memory.The
virtual-guestprofile is automatically selected when creating a Red Hat Enterprise Linux 7 guest virtual machine. It is the recommended profile for virtual machines.This profile is available in Red Hat Enterprise Linux 6.3 and later, but must be manually selected when installing a virtual machine.
- Based on the
virtual-hostalso enables more aggressive writeback of dirty pages. This profile is the recommended profile for virtualization hosts, including both KVM and Red Hat Virtualization (RHV) hosts.
By default in a Red Hat Enterprise Linux 7 installation, the tuned package is installed and the
tunedservice is enabled.
To list all available profiles and identify the current active profile, run:
# tuned-adm listAvailable profiles: - balanced - desktop - latency-performance - network-latency - network-throughput - powersave - sap - throughput-performance - virtual-guest - virtual-host Current active profile: throughput-performance
It is also possible to create custom tuned profiles to encapsulate a set of tuning parameters. For instructions on creating custom tuned profiles, see the
To only display the currently active profile, run:
To switch to one of the available profiles, run:
tuned-adm profile profile_name
For example, to switch to the
tuned-adm profile virtual-host
After setting a tuned profile in Red Hat Enterprise Linux 7.1 and above, make sure the tuned service is enabled for the configured profile to be applied after a reboot:
systemctl enable tuned
In some cases, it is preferable to disable tuned to use parameters set manually. To disable all tuning for the current session, run:
To permanently disable tuned and revert all changes it performed, run:
tuned-adm off; systemctl disable tuned
For further information about tuned, see the Red Hat Enterprise Linux 7 Performance Tuning Guide.