This documentation explains how to use the TuneD application to monitor and optimize the throughput, latency, and power consumption of your system in different scenarios.
Getting started with TuneD
As a system administrator, you can use the TuneD application to optimize the performance profile of your system for a variety of use cases.
The purpose of TuneD
TuneD is a service that monitors your system and optimizes the performance under certain workloads. The core of TuneD are profiles, which tune your system for different use cases.
TuneD is distributed with a number of predefined profiles for use cases such as:
-
High throughput
-
Low latency
-
Saving power
It is possible to modify the rules defined for each profile and customize how to tune a particular device. When you switch to another profile or deactivate TuneD, all changes made to the system settings by the previous profile revert back to their original state.
You can also configure TuneD to react to changes in device usage and adjusts settings to improve performance of active devices and reduce power consumption of inactive devices.
TuneD profiles
A detailed analysis of a system can be very time-consuming. TuneD provides a number of predefined profiles for typical use cases. You can also create, modify, and delete profiles.
The profiles provided with TuneD are divided into the following categories:
-
Power-saving profiles
-
Performance-boosting profiles
The performance-boosting profiles include profiles that focus on the following aspects:
-
Low latency for storage and network
-
High throughput for storage and network
-
Virtual machine performance
-
Virtualization host performance
The tuned.conf file can contain one [main] section and other sections for configuring plug-in instances. However, all sections are optional.
Lines starting with the hash sign (#) are comments.
-
tuned.conf(5)man page.
The default TuneD profile
During the installation, the best profile for your system is selected automatically. Currently, the default profile is selected according to the following customizable rules:
| Environment | Default profile | Goal |
|---|---|---|
Compute nodes |
|
The best throughput performance |
Virtual machines |
|
The best performance. If you are not interested in the best performance, you can change it to the |
Other cases |
|
Balanced performance and power consumption |
-
tuned.conf(5)man page.
Merged TuneD profiles
As an experimental feature, it is possible to select more profiles at once. TuneD will try to merge them during the load.
If there are conflicts, the settings from the last specified profile takes precedence.
The following example optimizes the system to run in a virtual machine for the best performance and concurrently tunes it for low power consumption, while the low power consumption is the priority:
# tuned-adm profile virtual-guest powersave
|
Warning
|
Merging is done automatically without checking whether the resulting combination of parameters makes sense. Consequently, the feature might tune some parameters the opposite way, which might be counterproductive: for example, setting the disk for high throughput by using the throughput-performance profile and concurrently setting the disk spindown to the low value by the spindown-disk profile. |
-
tuned.conf(5)man page.
The location of TuneD profiles
TuneD stores profiles in the following directories:
-
[filename]
/usr/lib/tuned/ -
Distribution-specific profiles are stored in the [filename]
/usr/lib/tuned/directory. Each profile has its own directory. The profile consists of the main configuration file calledtuned.conf, and optionally other files, for example helper scripts. -
[filename]
/etc/tuned/ -
If you need to customize a profile, copy the profile directory into the [filename]
/etc/tuned/directory, which is used for custom profiles, and then adjust it. If there is a system profile and a custom profile of the same name, the custom profile located in [filename]/etc/tuned/is used.
If you want to make TuneD load profiles from a directory other than [filename]/usr/lib/tuned/ and [filename]/etc/tuned/, you can list it in [filename]/etc/tuned/tuned-main.conf as follows:
profile_dirs=/usr/lib/tuned,/etc/tuned,/my/custom/profiles
In this example, profiles are loaded also from [filename]/my/custom/profiles/. If two directories contain profiles with the same names, the one that is listed later takes precedence.
-
tuned.conf(5)man page.
TuneD profiles distributed with RHEL
The following is a list of profiles that are installed with TuneD on Red Hat Enterprise Linux.
|
Note
|
There might be more product-specific or third-party TuneD profiles available. Such profiles are usually provided by separate RPM packages. |
-
balanced -
The default power-saving profile. It is intended to be a compromise between performance and power consumption. It uses auto-scaling and auto-tuning whenever possible. The only drawback is the increased latency. In the current TuneD release, it enables the CPU, disk, audio, and video plugins, and activates the
conservativeCPU governor. Theradeon_powersaveoption uses thedpm-balancedvalue if it is supported, otherwise it is set toauto.It changes the
energy_performance_preferenceattribute to thenormalenergy setting. It also changes thescaling_governorpolicy attribute to either theconservativeorpowersaveCPU governor. -
powersave -
A profile for maximum power saving performance. It can throttle the performance in order to minimize the actual power consumption. In the current TuneD release it enables USB autosuspend, WiFi power saving, and Aggressive Link Power Management (ALPM) power savings for SATA host adapters. It also schedules multi-core power savings for systems with a low wakeup rate and activates the
ondemandgovernor. It enables AC97 audio power saving or, depending on your system, HDA-Intel power savings with a 10 seconds timeout. If your system contains a supported Radeon graphics card with enabled KMS, the profile configures it to automatic power saving. On ASUS Eee PCs, a dynamic Super Hybrid Engine is enabled.It changes the
energy_performance_preferenceattribute to thepowersaveorpowerenergy setting. It also changes thescaling_governorpolicy attribute to either theondemandorpowersaveCPU governor.NoteIn certain cases, the
balancedprofile is more efficient compared to thepowersaveprofile.Consider there is a defined amount of work that needs to be done, for example a video file that needs to be transcoded. Your machine might consume less energy if the transcoding is done on the full power, because the task is finished quickly, the machine starts to idle, and it can automatically step-down to very efficient power save modes. On the other hand, if you transcode the file with a throttled machine, the machine consumes less power during the transcoding, but the process takes longer and the overall consumed energy can be higher.
That is why the
balancedprofile can be generally a better option. -
throughput-performance -
A server profile optimized for high throughput. It disables power savings mechanisms and enables
sysctlsettings that improve the throughput performance of the disk and network IO. CPU governor is set toperformance.It changes the
energy_performance_preferenceandscaling_governorattribute to theperformanceprofile. -
accelerator-performance -
The
accelerator-performanceprofile contains the same tuning as thethroughput-performanceprofile. Additionally, it locks the CPU to low C states so that the latency is less than 100us. This improves the performance of certain accelerators, such as GPUs. -
latency-performance -
A server profile optimized for low latency. It disables power savings mechanisms and enables
sysctlsettings that improve latency. CPU governor is set toperformanceand the CPU is locked to the low C states (by PM QoS).It changes the
energy_performance_preferenceandscaling_governorattribute to theperformanceprofile. -
network-latency -
A profile for low latency network tuning. It is based on the
latency-performanceprofile. It additionally disables transparent huge pages and NUMA balancing, and tunes several other network-relatedsysctlparameters.It inherits the
latency-performanceprofile which changes theenergy_performance_preferenceandscaling_governorattribute to theperformanceprofile. -
hpc-compute -
A profile optimized for high-performance computing. It is based on the
latency-performanceprofile. -
network-throughput -
A profile for throughput network tuning. It is based on the
throughput-performanceprofile. It additionally increases kernel network buffers.It inherits either the
latency-performanceorthroughput-performanceprofile, and changes theenergy_performance_preferenceandscaling_governorattribute to theperformanceprofile. -
virtual-guest -
A profile designed for virtual guests based on the
throughput-performanceprofile that, among other tasks, decreases virtual memory swappiness and increases disk readahead values. It does not disable disk barriers.It inherits the
throughput-performanceprofile and changes theenergy_performance_preferenceandscaling_governorattribute to theperformanceprofile. -
virtual-host -
A profile designed for virtual hosts based on the
throughput-performanceprofile that, among other tasks, decreases virtual memory swappiness, increases disk readahead values, and enables a more aggressive value of dirty pages writeback.It inherits the
throughput-performanceprofile and changes theenergy_performance_preferenceandscaling_governorattribute to theperformanceprofile. -
oracle -
A profile optimized for Oracle databases loads based on
throughput-performanceprofile. It additionally disables transparent huge pages and modifies other performance-related kernel parameters. This profile is provided by the [package]tuned-profiles-oraclepackage. -
desktop -
A profile optimized for desktops, based on the
balancedprofile. It additionally enables scheduler autogroups for better response of interactive applications. -
cpu-partitioning -
The
cpu-partitioningprofile partitions the system CPUs into isolated and housekeeping CPUs. To reduce jitter and interruptions on an isolated CPU, the profile clears the isolated CPU from user-space processes, movable kernel threads, interrupt handlers, and kernel timers.A housekeeping CPU can run all services, shell processes, and kernel threads.
You can configure the
cpu-partitioningprofile in/etc/tuned/cpu-partitioning-variables.conffile. The configuration options are:-
isolated_cores=_cpu-list_ -
Lists CPUs to isolate. The list of isolated CPUs is comma-separated or the user can specify the range. You can specify a range using a dash, such as
3-5. This option is mandatory. Any CPU missing from this list is automatically considered a housekeeping CPU. -
no_balance_cores=_cpu-list_ -
Lists CPUs which are not considered by the kernel during system wide process load-balancing. This option is optional. This is usually the same list as
isolated_cores.
For more information on
cpu-partitioning, see thetuned-profiles-cpu-partitioning(7)man page. -
-
optimize-serial-console -
A profile that tunes down I/O activity to the serial console by reducing the printk value. This should make the serial console more responsive. This profile is intended to be used as an overlay on other profiles. For example:
# tuned-adm profile throughput-performance optimize-serial-console -
mssql -
A profile provided for Microsoft SQL Server. It is based on the
thoguhput-performanceprofile. -
postgresql -
A profile optimized for PostgreSQL databases loads based on
throughput-performanceprofile. It additionally disables transparent huge pages and modifies other performance-related kernel parameters. This profile is provided by the [package]tuned-profiles-postgresqlpackage. -
intel-sst -
A profile optimized for systems with user-defined Intel Speed Select Technology configurations. This profile is intended to be used as an overlay on other profiles. For example:
# tuned-adm profile cpu-partitioning intel-sst
Real-time TuneD profiles distributed with RHEL
Real-time profiles are intended for systems running the real-time kernel. Without a special kernel build, they do not configure the system to be real-time. On RHEL, the profiles are available from additional repositories.
The following real-time profiles are available:
-
realtime -
Use on bare-metal real-time systems.
Provided by the [package]
tuned-profiles-realtimepackage, which is available from the RT or NFV repositories. -
realtime-virtual-host -
Use in a virtualization host configured for real-time.
Provided by the [package]
tuned-profiles-nfv-hostpackage, which is available from the NFV repository. -
realtime-virtual-guest -
Use in a virtualization guest configured for real-time.
Provided by the [package]
tuned-profiles-nfv-guestpackage, which is available from the NFV repository.
Static and dynamic tuning in TuneD
This section explains the difference between the two categories of system tuning that TuneD applies: static and dynamic.
- Static tuning
-
Mainly consists of the application of predefined
sysctlandsysfssettings and one-shot activation of several configuration tools such asethtool. - Dynamic tuning
-
Watches how various system components are used throughout the uptime of your system. TuneD adjusts system settings dynamically based on that monitoring information.
For example, the hard drive is used heavily during startup and login, but is barely used later when the user might mainly work with applications such as web browsers or email clients. Similarly, the CPU and network devices are used differently at different times. TuneD monitors the activity of these components and reacts to the changes in their use.
By default, dynamic tuning is disabled. To enable it, edit the [filename]
/etc/tuned/tuned-main.conffile and change the [option]dynamic_tuningoption to1. TuneD then periodically analyzes system statistics and uses them to update your system tuning settings. To configure the time interval in seconds between these updates, use the [option]update_intervaloption.Currently implemented dynamic tuning algorithms try to balance the performance and powersave, and are therefore disabled in the performance profiles. Dynamic tuning for individual plug-ins can be enabled or disabled in the TuneD profiles.
On a typical office workstation, the Ethernet network interface is inactive most of the time. Only a few emails go in and out or some web pages might be loaded.
For those kinds of loads, the network interface does not have to run at full speed all the time, as it does by default. TuneD has a monitoring and tuning plug-in for network devices that can detect this low activity and then automatically lower the speed of that interface, typically resulting in a lower power usage.
If the activity on the interface increases for a longer period of time, for example because a DVD image is being downloaded or an email with a large attachment is opened, TuneD detects this and sets the interface speed to maximum to offer the best performance while the activity level is high.
This principle is used for other plug-ins for CPU and disks as well.
TuneD no-daemon mode
You can run TuneD in no-daemon mode, which does not require any resident memory. In this mode, TuneD applies the settings and exits.
By default, no-daemon mode is disabled because a lot of TuneD functionality is missing in this mode, including:
-
D-Bus support
-
Hot-plug support
-
Rollback support for settings
To enable no-daemon mode, include the following line in the [filename]/etc/tuned/tuned-main.conf file:
daemon = 0
Installing and enabling TuneD
This procedure installs and enables the TuneD application, installs TuneD profiles, and presets a default TuneD profile for your system.
-
Install the [package]
tunedpackage:# yum install tuned -
Enable and start the
tunedservice:# systemctl enable --now tuned -
Optionally, install TuneD profiles for real-time systems:
# yum install tuned-profiles-realtime tuned-profiles-nfv -
Verify that a TuneD profile is active and applied:
$ tuned-adm active Current active profile: balanced$ tuned-adm verify Verification succeeded, current system settings match the preset profile. See TuneD log file ('/var/log/tuned/tuned.log') for details.
Listing available TuneD profiles
This procedure lists all TuneD profiles that are currently available on your system.
-
To list all available TuneD profiles on your system, use:
$ tuned-adm list Available profiles: - balanced - General non-specialized tuned profile - desktop - Optimize for the desktop use-case - latency-performance - Optimize for deterministic performance at the cost of increased power consumption - network-latency - Optimize for deterministic performance at the cost of increased power consumption, focused on low latency network performance - network-throughput - Optimize for streaming network throughput, generally only necessary on older CPUs or 40G+ networks - powersave - Optimize for low power consumption - throughput-performance - Broadly applicable tuning that provides excellent performance across a variety of common server workloads - virtual-guest - Optimize for running inside a virtual guest - virtual-host - Optimize for running KVM guests Current active profile: balanced -
To display only the currently active profile, use:
$ tuned-adm active Current active profile: balanced
-
The
tuned-adm(8)man page.
Setting a TuneD profile
This procedure activates a selected TuneD profile on your system.
-
The
tunedservice is running. See Installing and Enabling Tuned for details.
-
Optionally, you can let TuneD recommend the most suitable profile for your system:
# tuned-adm recommend balanced -
Activate a profile:
# tuned-adm profile selected-profileAlternatively, you can activate a combination of multiple profiles:
# tuned-adm profile profile1 profile2Example 4. A virtual machine optimized for low power consumptionThe following example optimizes the system to run in a virtual machine with the best performance and concurrently tunes it for low power consumption, while the low power consumption is the priority:
# tuned-adm profile virtual-guest powersave -
View the current active TuneD profile on your system:
# tuned-adm active Current active profile: selected-profile -
Reboot the system:
# reboot
-
Verify that the TuneD profile is active and applied:
$ tuned-adm verify Verification succeeded, current system settings match the preset profile. See TuneD log file ('/var/log/tuned/tuned.log') for details.
-
tuned-adm(8)man page
Disabling TuneD
This procedure disables TuneD and resets all affected system settings to their original state before TuneD modified them.
-
To disable all tunings temporarily:
# tuned-adm offThe tunings are applied again after the
tunedservice restarts. -
Alternatively, to stop and disable the
tunedservice permanently:# systemctl disable --now tuned
-
tuned-adm(8)man page
Related information
-
The
tuned(8)man page -
The
tuned-adm(8)man page -
The TuneD project website: https://tuned-project.org/
Customizing TuneD profiles
You can create or modify TuneD profiles to optimize system performance for your intended use case.
-
Install and enable TuneD as described in Installing and Enabling Tuned for details.
TuneD profiles
A detailed analysis of a system can be very time-consuming. TuneD provides a number of predefined profiles for typical use cases. You can also create, modify, and delete profiles.
The profiles provided with TuneD are divided into the following categories:
-
Power-saving profiles
-
Performance-boosting profiles
The performance-boosting profiles include profiles that focus on the following aspects:
-
Low latency for storage and network
-
High throughput for storage and network
-
Virtual machine performance
-
Virtualization host performance
The tuned.conf file can contain one [main] section and other sections for configuring plug-in instances. However, all sections are optional.
Lines starting with the hash sign (#) are comments.
-
tuned.conf(5)man page.
The default TuneD profile
During the installation, the best profile for your system is selected automatically. Currently, the default profile is selected according to the following customizable rules:
| Environment | Default profile | Goal |
|---|---|---|
Compute nodes |
|
The best throughput performance |
Virtual machines |
|
The best performance. If you are not interested in the best performance, you can change it to the |
Other cases |
|
Balanced performance and power consumption |
-
tuned.conf(5)man page.
Merged TuneD profiles
As an experimental feature, it is possible to select more profiles at once. TuneD will try to merge them during the load.
If there are conflicts, the settings from the last specified profile takes precedence.
The following example optimizes the system to run in a virtual machine for the best performance and concurrently tunes it for low power consumption, while the low power consumption is the priority:
# tuned-adm profile virtual-guest powersave
|
Warning
|
Merging is done automatically without checking whether the resulting combination of parameters makes sense. Consequently, the feature might tune some parameters the opposite way, which might be counterproductive: for example, setting the disk for high throughput by using the throughput-performance profile and concurrently setting the disk spindown to the low value by the spindown-disk profile. |
-
tuned.conf(5)man page.
The location of TuneD profiles
TuneD stores profiles in the following directories:
-
[filename]
/usr/lib/tuned/ -
Distribution-specific profiles are stored in the [filename]
/usr/lib/tuned/directory. Each profile has its own directory. The profile consists of the main configuration file calledtuned.conf, and optionally other files, for example helper scripts. -
[filename]
/etc/tuned/ -
If you need to customize a profile, copy the profile directory into the [filename]
/etc/tuned/directory, which is used for custom profiles, and then adjust it. If there is a system profile and a custom profile of the same name, the custom profile located in [filename]/etc/tuned/is used.
If you want to make TuneD load profiles from a directory other than [filename]/usr/lib/tuned/ and [filename]/etc/tuned/, you can list it in [filename]/etc/tuned/tuned-main.conf as follows:
profile_dirs=/usr/lib/tuned,/etc/tuned,/my/custom/profiles
In this example, profiles are loaded also from [filename]/my/custom/profiles/. If two directories contain profiles with the same names, the one that is listed later takes precedence.
-
tuned.conf(5)man page.
Inheritance between TuneD profiles
TuneD profiles can be based on other profiles and modify only certain aspects of their parent profile.
The [main] section of TuneD profiles recognizes the [option]include option:
[main]
include=parent
All settings from the parent profile are loaded in this child profile. In the following sections, the child profile can override certain settings inherited from the parent profile or add new settings not present in the parent profile.
You can create your own child profile in the [filename]/etc/tuned/ directory based on a pre-installed profile in [filename]/usr/lib/tuned/ with only some parameters adjusted.
If the parent profile is updated, such as after a TuneD upgrade, the changes are reflected in the child profile.
The following is an example of a custom profile that extends the balanced profile and disables the capability of the CPU to boost above nominal frequencies for brief periods.
[main]
include=balanced
[cpu]
boost=0
-
tuned.conf(5)man page
Static and dynamic tuning in TuneD
This section explains the difference between the two categories of system tuning that TuneD applies: static and dynamic.
- Static tuning
-
Mainly consists of the application of predefined
sysctlandsysfssettings and one-shot activation of several configuration tools such asethtool. - Dynamic tuning
-
Watches how various system components are used throughout the uptime of your system. TuneD adjusts system settings dynamically based on that monitoring information.
For example, the hard drive is used heavily during startup and login, but is barely used later when the user might mainly work with applications such as web browsers or email clients. Similarly, the CPU and network devices are used differently at different times. TuneD monitors the activity of these components and reacts to the changes in their use.
By default, dynamic tuning is disabled. To enable it, edit the [filename]
/etc/tuned/tuned-main.conffile and change the [option]dynamic_tuningoption to1. TuneD then periodically analyzes system statistics and uses them to update your system tuning settings. To configure the time interval in seconds between these updates, use the [option]update_intervaloption.Currently implemented dynamic tuning algorithms try to balance the performance and powersave, and are therefore disabled in the performance profiles. Dynamic tuning for individual plug-ins can be enabled or disabled in the TuneD profiles.
On a typical office workstation, the Ethernet network interface is inactive most of the time. Only a few emails go in and out or some web pages might be loaded.
For those kinds of loads, the network interface does not have to run at full speed all the time, as it does by default. TuneD has a monitoring and tuning plug-in for network devices that can detect this low activity and then automatically lower the speed of that interface, typically resulting in a lower power usage.
If the activity on the interface increases for a longer period of time, for example because a DVD image is being downloaded or an email with a large attachment is opened, TuneD detects this and sets the interface speed to maximum to offer the best performance while the activity level is high.
This principle is used for other plug-ins for CPU and disks as well.
TuneD plug-ins
Plug-ins are modules in TuneD profiles that TuneD uses to monitor or optimize different devices on the system.
TuneD uses two types of plug-ins:
- Monitoring plug-ins
-
Monitoring plug-ins are used to get information from a running system. The output of the monitoring plug-ins can be used by tuning plug-ins for dynamic tuning.
Monitoring plug-ins are automatically instantiated whenever their metrics are needed by any of the enabled tuning plug-ins. If two tuning plug-ins require the same data, only one instance of the monitoring plug-in is created and the data is shared.
- Tuning plug-ins
-
Each tuning plug-in tunes an individual subsystem and takes several parameters that are populated from the TuneD profiles. Each subsystem can have multiple devices, such as multiple CPUs or network cards, that are handled by individual instances of the tuning plug-ins. Specific settings for individual devices are also supported.
Sections describing plug-in instances are formatted in the following way:
[NAME]
type=TYPE
devices=DEVICES
- NAME
-
is the name of the plug-in instance as it is used in the logs. It can be an arbitrary string.
- TYPE
-
is the type of the tuning plug-in.
- DEVICES
-
is the list of devices that this plug-in instance handles.
The
devicesline can contain a list, a wildcard (\*), and negation (!). If there is nodevicesline, all devices present or later attached on the system of the TYPE are handled by the plug-in instance. This is same as using the [option]devices=*option.Example 9. Matching block devices with a plug-inThe following example matches all block devices starting with
sd, such assdaorsdb, and does not disable barriers on them:[data_disk] type=disk devices=sd* disable_barriers=falseThe following example matches all block devices except
sda1andsda2:[data_disk] type=disk devices=!sda1, !sda2 disable_barriers=false
If no instance of a plug-in is specified, the plug-in is not enabled.
If the plug-in supports more options, they can be also specified in the plug-in section. If the option is not specified and it was not previously specified in the included plug-in, the default value is used.
If you do not need custom names for the plug-in instance and there is only one definition of the instance in your configuration file, TuneD supports the following short syntax:
[TYPE]
devices=DEVICES
In this case, it is possible to omit the type line. The instance is then referred to with a name, same as the type. The previous example could be then rewritten into:
[disk]
devices=sdb*
disable_barriers=false
If the same section is specified more than once using the include option, the settings are merged. If they cannot be merged due to a conflict, the last conflicting definition overrides the previous settings. If you do not know what was previously defined, you can use the [option]replace Boolean option and set it to true. This causes all the previous definitions with the same name to be overwritten and the merge does not happen.
You can also disable the plug-in by specifying the [option]enabled=false option. This has the same effect as if the instance was never defined. Disabling the plug-in is useful if you are redefining the previous definition from the [option]include option and do not want the plug-in to be active in your custom profile.
- NOTE
-
TuneD includes the ability to run any shell command as part of enabling or disabling a tuning profile. This enables you to extend TuneD profiles with functionality that has not been integrated into TuneD yet.
You can specify arbitrary shell commands using the
scriptplug-in.
-
tuned.conf(5)man page
Available TuneD plug-ins
This section lists all monitoring and tuning plug-ins currently available in TuneD.
acpi
Configures the ACPI driver.
The only currently supported option is
[option]platform_profile, which sets the ACPI
platform profile sysfs attribute,
a generic power/performance preference API for other drivers.
Multiple profiles can be specified, separated by |.
The first available profile is selected.
[acpi]
platform_profile=balanced|low-power
Using this option, TuneD will try to set the platform profile
to balanced. If that fails, it will try to set it to low-power.
audio
Sets audio cards power saving options. The plug-in sets the auto suspend
timeout for audio codecs to the value specified by the [option]timeout
option.
Currently, the snd_hda_intel and snd_ac97_codec codecs are
supported and the [option]timeout value is in seconds. To disable
auto suspend for these codecs, set the [option]timeout value
to 0. To enforce the controller reset, set the option
[option]reset_controller to true. Note that power management
is supported per module. Hence, the kernel module names are used as
device names.
[audio]
timeout=10
reset_controller=true
bootloader
Adds options to the kernel command line. This plug-in supports the GRUB 2 boot loader and the Boot Loader Specification (BLS).
|
Note
|
TuneD will not remove or replace kernel command line parameters added via other methods like grubby. TuneD will manage the kernel command line parameters added via TuneD. Please refer to your platform bootloader documentation about how to identify and manage kernel command line parameters set outside of TuneD. |
Customized non-standard location of the GRUB 2 configuration file
can be specified by the [option]grub2_cfg_file option.
The kernel options are added to the current GRUB configuration and its templates. Reboot the system for the kernel option to take effect.
Switching to another profile or manually stopping the tuned
service removes the additional options. If you shut down or reboot
the system, the kernel options persist in the [filename]grub.cfg
file and grub environment files.
The kernel options can be specified by the following syntax:
cmdlinesuffix=arg1 arg2 ... argN
Or with an alternative, but equivalent syntax:
cmdlinesuffix=+arg1 arg2 ... argN
Where suffix can be arbitrary (even empty) alphanumeric
string which should be unique across all loaded profiles. It is
recommended to use the profile name as the suffix
(for example, [option]cmdline_my_profile). If there are multiple
[option]cmdline options with the same suffix, during the profile
load/merge the value which was assigned previously will be used. This
is the same behavior as any other plug-in options. The final kernel
command line is constructed by concatenating all the resulting
[option]cmdline options.
It is also possible to remove kernel options by the following syntax:
cmdlinesuffix=-arg1 arg2 ... argN
Such kernel options will not be concatenated and thus removed during the final kernel command line construction.
For example, to add the [option]quiet kernel option to a TuneD
profile, include the following lines in the [filename]tuned.conf
file:
[bootloader]
cmdline_my_profile=+quiet
An example of a custom profile my_profile that adds the
[option]isolcpus=2 option to the kernel command line:
[bootloader]
cmdline_my_profile=isolcpus=2
An example of a custom profile my_profile that removes the
[option]rhgb quiet options from the kernel command line (if
previously added by TuneD):
[bootloader]
cmdline_my_profile=-rhgb quiet
For example, to add the [option]rhgb quiet kernel options to a
TuneD profile profile_1:
[bootloader]
cmdline_profile_1=+rhgb quiet
In the child profile profile_2 drop the [option]quiet option
from the kernel command line:
[main]
include=profile_1
[bootloader]
cmdline_profile_2=-quiet
The final kernel command line will be [option]rhgb. In case the same
[option]cmdline suffix as in the profile_1 is used:
[main]
include=profile_1
[bootloader]
cmdline_profile_1=-quiet
It will result in the empty kernel command line because the merge
executes and the [option]cmdline_profile_1 gets redefined to just
[option]-quiet. Thus there is nothing to remove in the final kernel
command line processing.
The [option]initrd_add_img=IMAGE adds an initrd overlay file
IMAGE. If the IMAGE file name begins with /, the absolute path is
used. Otherwise, the current profile directory is used as the base
directory for the IMAGE.
The [option]initrd_add_dir=DIR creates an initrd image from the
directory DIR and adds the resulting image as an overlay.
If the DIR directory name begins with /, the absolute path
is used. Otherwise, the current profile directory is used as the
base directory for the DIR.
The [option]initrd_dst_img=PATHNAME sets the name and location of
the resulting initrd image. Typically, it is not necessary to use this
option. By default, the location of initrd images is /boot and the
name of the image is taken as the basename of IMAGE or DIR. This can
be overridden by setting [option]initrd_dst_img.
The [option]initrd_remove_dir=VALUE removes the source directory
from which the initrd image was built if VALUE is true. Only y,
yes, t, true and 1 (case insensitive) are accepted as true
values for this option. Other values are interpreted as false.
[bootloader]
initrd_remove_dir=True
initrd_add_dir=/tmp/tuned-initrd.img
This creates an initrd image from the /tmp/tuned-initrd.img directory
and and then removes the tuned-initrd.img directory from /tmp.
The [option]skip_grub_config=VALUE does not change grub
configuration if VALUE is true. However, [option]cmdline
options are still processed, and the result is used to verify the current
cmdline. Only y, yes, t, true and 1 (case insensitive) are accepted
as true values for this option. Other values are interpreted as false.
[bootloader]
skip_grub_config=True
cmdline=+systemd.cpu_affinity=1
disk
Plug-in for tuning various block device options. This plug-in can also
dynamically change the advanced power management and spindown timeout
setting for a drive according to the current drive utilization. The
dynamic tuning is controlled by the [option]dynamic and the global
[option]dynamic_tuning option in tuned-main.conf.
The disk plug-in operates on all supported block devices unless a
comma separated list of [option]devices is passed to it.
sda block device[disk]
devices=sda
The [option]elevator option sets the Linux I/O scheduler.
xvda block device[disk]
device=xvda
elevator=bfq
The [option]scheduler_quantum option only applies to the CFQ I/O
scheduler. It defines the number of I/O requests that CFQ sends to
one device at one time, essentially limiting queue depth. The default
value is 8 requests. The device being used may support greater queue
depth, but increasing the value of quantum will also increase latency,
especially for large sequential write work loads.
The [option]apm option sets the Advanced Power Management feature
on drives that support it. It corresponds to using the -B option of
the hdparm utility. The [option]spindown option puts the drive
into idle (low-power) mode, and also sets the standby (spindown)
timeout for the drive. It corresponds to using -S option of the
hdparm utility.
[disk]
apm=128
spindown=6
The [option]readahead option controls how much extra data the
operating system reads from disk when performing sequential
I/O operations. Increasing the readahead value might improve
performance in application environments where sequential reading of
large files takes place. The default unit for readahead is KiB. This
can be adjusted to sectors by specifying the suffix s. If the
suffix is specified, there must be at least one space between the
number and suffix (for example, readahead=8192 s).
readahead to 4MB unless already set to a higher value[disk]
readahead=>4096
The disk readahead value can be multiplied by the constant
specified by the [option]readahead_multiply option.
eeepc_she
Dynamically sets the front-side bus (FSB) speed according to the
CPU load. This feature can be found on some netbooks and is also
known as the Asus Super Hybrid Engine. If the CPU load is lower or
equal to the value specified by the [option]load_threshold_powersave
option, the plug-in sets the FSB speed to the value specified by the
[option]she_powersave option. If the CPU load is higher or
equal to the value specified by the [option]load_threshold_normal
option, it sets the FSB speed to the value specified by the
[option]she_normal option. Static tuning is not supported and the
plug-in is transparently disabled if the hardware support for this
feature is not detected.
|
Note
|
For details about the FSB frequencies and corresponding values, see the kernel documentation. The provided defaults should work for most users. |
irq
Allows tuning of IRQ affinities, and thus re-implements functionality
already present in the scheduler plugin. However, this plugin offers
more flexibility, as it allows tuning of individual interrupts with
different affinities. When using the irq plugin, make sure to disable
IRQ processing in the scheduler plugin by setting its option
[option]irq_process=false.
The plugin handles individual IRQs as devices and multiple plugin
instances can be defined, each addressing different devices/irqs.
The device names used by the plugin are irq<n>, where <n> is the
IRQ number. The special device DEFAULT controls values written to
/proc/irq/default_smp_affinity, which applies to all non-active IRQs.
The option [option]affinity controls the IRQ affinity to be set. It is
a string in "cpulist" format (such as 1,3-4). If the configured affinity
is empty, then the affinity of the respective IRQs is not touched.
The option [option]mode is a string which can either be set (default)
or intersect. In set mode the [option]affinity is always written
as configured, whereas in intersect mode, the new affinity will be
calculated as the intersection of the current and the configured affinity.
If that intersection is empty, the configured affinity will be used.
[irq_special]
type=irq
devices=irq16
affinity=2
[irq]
affinity=0
irqbalance
Plug-in for irqbalance settings management. The plug-in
configures CPUs which should be skipped when rebalancing IRQs in
/etc/sysconfig/irqbalance. It then restarts irqbalance if and
only if it was previously running.
The banned/skipped CPUs are specified as a CPU list via the
[option]banned_cpus option.
[irqbalance]
banned_cpus=2,4,9-13
modules
Plug-in for applying custom kernel modules options.
This plug-in can set parameters to kernel modules. It creates
/etc/modprobe.d/tuned.conf file. The syntax is
_module_=_option1=value1 option2=value2..._ where _module_ is
the module name and _optionx=valuex_ are module options which may
or may not be present.
netrom with module parameter nr_ndevs=2[modules]
netrom=nr_ndevs=2
Modules can also be forced to load/reload by using an additional
+r option prefix.
netrom with module parameter nr_ndevs=2[modules]
netrom=+r nr_ndevs=2
The +r switch will also cause TuneD to try and remove netrom
module (if loaded) and try and (re)insert it with the specified
parameters. The +r can be followed by an optional comma (+r,)
for better readability.
When using +r the module will be loaded immediately by the TuneD
daemon itself rather than waiting for the OS to load it with the
specified parameters.
mounts
Enables or disables barriers for mounts according to the value of the
boolean option [option]disable_barriers. The option additionally allows
the special value force, which disables barriers even on mountpoints with
write back caches.
|
Note
|
Only extended file systems (ext) are supported by this plug-in. |
net
Configures network driver, hardware and Netfilter settings.
Dynamic change of the interface speed according to the interface
utilization is also supported. The dynamic tuning is controlled by
the [option]dynamic and the global [option]dynamic_tuning
option in tuned-main.conf.
-
wake_on_lan -
The [option]
wake_on_lanoption sets wake-on-lan to the specified value as when using theethtoolutility.Example 25. Set Wake-on-LAN for device eth0 on MagicPacket™[net] devices=eth0 wake_on_lan=g -
coalesce -
The [option]
coalesceoption allows changing coalescing settings for the specified network devices. The syntax is:coalesce=param1 value1 param2 value2 ... paramN valueNNote that not all the coalescing parameters are supported by all network cards. For the list of coalescing parameters of your network device, use
ethtool -c device.Example 26. Setting coalescing parameters rx/tx-usecs for all network devices[net] coalesce=rx-usecs 3 tx-usecs 16 -
features -
The [option]
featuresoption allows changing the offload parameters and other features for the specified network devices. To query the features of your network device, useethtool -k device. The syntax of the option is the same as the [option]coalesceoption.Example 27. Turn off TX checksumming, generic segmentation and receive offload[net] features=tx off gso off gro off -
pause -
The [option]
pauseoption allows changing the pause parameters for the specified network devices. To query the pause parameters of your network device, useethtool -a device. The syntax of the option is the same as the [option]coalesceoption.Example 28. Disable autonegotiation[net] pause=autoneg off -
ring -
The [option]
ringoption allows changing the rx/tx ring parameters for the specified network devices. To query the ring parameters of your network device, useethtool -g device. The syntax of the option is the same as the [option]coalesceoption.Example 29. Change the number of ring entries for the Rx/Tx rings to 1024/512 respectively[net] ring=rx 1024 tx 512 -
channels -
The [option]
channelsoption allows changing the numbers of channels for the specified network device. A channel is an IRQ and the set of queues that can trigger that IRQ. To query the channels parameters of your network device, useethtool -l device. The syntax of the option is the same as the [option]coalesceoption.Example 30. Set the number of multi-purpose channels to 16[net] channels=combined 16A network device either supports rx/tx or combined queue mode. The [option]
channelsoption automatically adjusts the parameters based on the mode supported by the device as long as a valid configuration is requested. -
nf_conntrack_hashsize -
The [option]
nf_conntrack_hashsizeoption sets the size of the hash table which stores lists of conntrack entries by writing to/sys/module/nf_conntrack/parameters/hashsize.Example 31. Adjust the size of the conntrack hash table[net] nf_conntrack_hashsize=131072 -
txqueuelen -
The [option]
txqueuelenoption allows changing txqueuelen (the length of the transmit queue). It usesiputility that is in package iproute recommended for TuneD, so the package needs to be installed for its correct functionality. To query the txqueuelen parameters of your network device useip link showand the current value is shown after the qlen column.Example 32. Adjust the length of the transmit queue[net] txqueuelen=5000 -
mtu -
The [option]
mtuoption allows changing MTU (Maximum Transmission Unit). It usesiputility that is in package iproute recommended for TuneD, so the package needs to be installed for its correct functionality. To query the MTU parameters of your network device useip link showand the current value is shown after the MTU column.Example 33. Adjust the size of the MTU[net] mtu=9000
rtentsk
A plug-in for avoiding inter-processor interrupts caused by enabling or disabling static keys.
The plug-in has no options; when included, TuneD will keep an open socket with timestamping enabled, thus keeping the static key enabled.
script
Executes an external script or binary when the profile is loaded or unloaded. You can choose an arbitrary executable.
|
Important
|
The script plug-in is provided mainly for compatibility
with earlier releases. Prefer other TuneD plug-ins if they cover
the required functionality. |
TuneD calls the executable with one of the following arguments:
-
startwhen loading the profile -
stopwhen unloading the profile
You need to correctly implement the stop action in your executable
and revert all settings that you changed during the start
action. Otherwise, the roll-back step after changing your TuneD
profile will not work.
Bash scripts can import the [filename]/usr/lib/tuned/functions
Bash library and use the functions defined there. Use these
functions only for functionality that is not natively provided
by TuneD. If a function name starts with an underscore, such as
_wifi_set_power_level, consider the function private and do not
use it in your scripts, because it might change in the future.
Specify the path to the executable using the script parameter in
the plug-in configuration.
To run a Bash script named script.sh that is located in the profile
directory, use:
[script]
script=${i:PROFILE_DIR}/script.sh
scsi_host
Tunes options for SCSI hosts.
The plug-in sets Aggressive Link Power Management (ALPM) to the value specified
by the [option]alpm option. The option takes one of four values:
min_power, med_power_with_dipm, medium_power and max_performance.
|
Note
|
ALPM is only available on SATA controllers that use the Advanced Host Controller Interface (AHCI). |
[scsi_host]
alpm=med_power_with_dipm
selinux
Plug-in for tuning SELinux options.
SELinux decisions, such as allowing or denying access, are
cached. This cache is known as the Access Vector Cache (AVC). When
using these cached decisions, SELinux policy rules need to be checked
less, which increases performance. The [option]avc_cache_threshold
option allows adjusting the maximum number of AVC entries.
|
Note
|
Prior to changing the default value, evaluate the system performance with care. Increasing the value could potentially decrease the performance by making AVC slow. |
[selinux]
avc_cache_threshold=8192
service
Plug-in for handling sysvinit, sysv-rc, openrc and systemd services.
The syntax is as follows:
[service]
service.service_name=commands[,file:file]
Supported service-handling _commands_ are start, stop, enable
and disable. The optional file:__file__ directive installs an overlay
configuration file __file__. Multiple commands must be comma (,)
or semicolon (;) separated. If the directives conflict, the last
one is used.
The service plugin supports configuration overlays only for systemd.
In other init systems, this directive is ignored. The configuration
overlay files are copied to /etc/systemd/system/__service_name__.service.d/
directories. Upon profile unloading, the directory is removed if it is empty.
With systemd, the start command is implemented by restart in order
to allow loading of the service configuration file overlay.
|
Note
|
With non-systemd init systems, the plug-in operates on the current runlevel only. |
sendmail service with an overlay file[service]
service.sendmail=start,enable,file:${i:PROFILE_DIR}/tuned-sendmail.conf
The internal variable ${i:PROFILE_DIR} points to the directory
from which the profile is loaded.
sysctl
Sets various kernel parameters at runtime.
This plug-in is used for applying custom sysctl settings and should
only be used to change system settings that are not covered by other
TuneD plug-ins. If the settings are covered by other TuneD plug-ins,
use those plug-ins instead.
The syntax for this plug-in is
_key_=_value_, where
_key_ is the same as the key name provided by the
sysctl utility.
[sysctl]
kernel.sched_min_granularity_ns=3000000
sysfs
Sets various sysfs settings specified by the plug-in options.
The syntax is _name_=_value_, where
_name_ is the sysfs path to use and _value_ is
the value to write. The sysfs path supports the shell-style
wildcard characters (see man 7 glob for additional detail).
Use this plugin in case you need to change some settings that are not covered by other plug-ins. Prefer specific plug-ins if they cover the required settings.
[sysfs]
/sys/devices/system/machinecheck/machinecheck*/ignore_ce=1
systemd
Plug-in for tuning systemd options.
The [option]cpu_affinity option allows setting CPUAffinity in
/etc/systemd/system.conf. This configures the CPU affinity for the
service manager as well as the default CPU affinity for all forked
off processes. The option takes a comma-separated list of CPUs with
optional CPU ranges specified by the minus sign (-).
systemd to 0 1 2 3[systemd]
cpu_affinity=0-3
|
Note
|
These tunings are unloaded only on profile change followed by a reboot. |
uncore
An Intel-specific plug-in for limiting the maximum and minimum uncore frequency.
The options [option]max_freq_khz, [option]min_freq_khz correspond to
sysfs files exposed by Intel uncore frequency driver. Their values can be
specified in kHz or as a percentage of their configurable range.
[uncore10]
type=uncore
devices=uncore10
max_freq_khz=4000000
[uncore_all]
type=uncore
max_freq_khz=90%
Using this options TuneD will limit maximum frequency of all uncore units on the Intel system to 90% of the allowable range. Except uncore10 which maximum frequency limit will be set to 4 GHz.
usb
Sets autosuspend timeout of USB devices to the value specified by the
[option]autosuspend option in seconds. If the [option]devices
option is specified, the [option]autosuspend option applies to only
the USB devices specified, otherwise it applies to all USB devices.
The value 0 means that autosuspend is disabled.
1-1 and 1-2[usb]
devices=1-1,1-2
autosuspend=0
video
Sets various power saving features on video cards.
Radeon cards are supported.
The powersave level can be specified
by using the [option]radeon_powersave option. Supported values are:
-
default -
auto -
low -
mid -
high -
dynpm -
dpm-battery -
dpm-balanced -
dpm-perfomance
For additional detail, see KMS Power Management Options.
|
Note
|
This plug-in is experimental and the option might change in future releases. |
[video]
radeon_powersave=high
Mobile hardware with amdgpu driven eDP panels can be configured
with the [option]panel_power_savings option.
This accepts a value range from 0 to 4, where 4 is the highest power savings
but will trade off color accuracy.
vm
Tunes selected sysctl options in /proc/sys/vm, currently
[option]dirty_ratio, [option]dirty_background_ratio,
[option]dirty_bytes, and [option]dirty_background_bytes.
See https://docs.kernel.org/admin-guide/sysctl/vm.html for detailed
documentation of these options.
Additionaly enables or disables transparent huge pages depending on
the value of the [option]transparent_hugepages option. The option
can have one of three possible values: always, madvise and never.
[vm]
transparent_hugepages=never
The [option]transparent_hugepage.defrag option specifies the
defragmentation policy. Possible values for this option are always,
defer, defer+madvise, madvise and never. For a detailed
explanation of these values refer to
Transparent Hugepage Support.
Variables in TuneD profiles
Variables expand at run time when a TuneD profile is activated.
Using TuneD variables reduces the amount of necessary typing in TuneD profiles.
There are no predefined variables in TuneD profiles. You can define your own variables by creating the [variables] section in a profile and using the following syntax:
[variables]
variable_name=value
To expand the value of a variable in a profile, use the following syntax:
${variable_name}
In the following example, the ${isolated_cores} variable expands to 1,2; hence the kernel boots with the [option]isolcpus=1,2 option:
[variables]
isolated_cores=1,2
[bootloader]
cmdline=isolcpus=${isolated_cores}
The variables can be specified in a separate file. For example, you can add the following lines to [filename]tuned.conf:
[variables]
include=/etc/tuned/my-variables.conf
[bootloader]
cmdline=isolcpus=${isolated_cores}
If you add the [option]isolated_cores=1,2 option to the [filename]/etc/tuned/my-variables.conf file, the kernel boots with the [option]isolcpus=1,2 option.
-
tuned.conf(5)man page
Built-in functions in TuneD profiles
Built-in functions expand at run time when a TuneD profile is activated.
You can:
-
Use various built-in functions together with TuneD variables
-
Create custom functions in Python and add them to TuneD in the form of plug-ins
To call a function, use the following syntax:
${f:function_name:argument_1:argument_2}
To expand the directory path where the profile and the tuned.conf file are located, use the PROFILE_DIR function, which requires special syntax:
${i:PROFILE_DIR}
In the following example, the ${non_isolated_cores} variable expands to 0,3-5, and the cpulist_invert built-in function is called with the 0,3-5 argument:
[variables]
non_isolated_cores=0,3-5
[bootloader]
cmdline=isolcpus=${f:cpulist_invert:${non_isolated_cores}}
The cpulist_invert function inverts the list of CPUs. For a 6-CPU machine, the inversion is 1,2, and the kernel boots with the [option]isolcpus=1,2 command-line option.
-
tuned.conf(5)man page
Built-in functions available in TuneD profiles
The following built-in functions are available in all TuneD profiles:
-
PROFILE_DIR -
Returns the directory path where the profile and the
tuned.conffile are located. -
exec -
Executes a process and returns its output.
-
assertion -
Compares two arguments. If they do not match, the function logs text from the first argument and aborts profile loading.
-
assertion_non_equal -
Compares two arguments. If they match, the function logs text from the first argument and aborts profile loading.
-
kb2s -
Converts kilobytes to disk sectors.
-
s2kb -
Converts disk sectors to kilobytes.
-
strip -
Creates a string from all passed arguments and deletes both leading and trailing white space.
-
virt_check -
Checks whether TuneD is running inside a virtual machine (VM) or on bare metal:
-
Inside a VM, the function returns the first argument.
-
On bare metal, the function returns the second argument, even in case of an error.
-
-
cpulist_invert -
Inverts a list of CPUs to make its complement. For example, on a system with 4 CPUs, numbered from 0 to 3, the inversion of the list
0,2,3is1. -
cpulist2hex -
Converts a CPU list to a hexadecimal CPU mask.
-
cpulist2hex_invert -
Converts a CPU list to a hexadecimal CPU mask and inverts it.
-
hex2cpulist -
Converts a hexadecimal CPU mask to a CPU list.
-
cpulist_online -
Checks whether the CPUs from the list are online. Returns the list containing only online CPUs.
-
cpulist_present -
Checks whether the CPUs from the list are present. Returns the list containing only present CPUs.
-
cpulist_unpack -
Unpacks a CPU list in the form of
1-3,4to1,2,3,4. -
cpulist_pack -
Packs a CPU list in the form of
1,2,3,5to1-3,5. -
intel_recommended_pstate -
Returns recommended intel_pstate CPUFreq driver mode based on processor generation.
Creating new TuneD profiles
This procedure creates a new TuneD profile with custom performance rules.
-
The
tunedservice is running. See Installing and Enabling Tuned for details.
-
In the [filename]
/etc/tuned/directory, create a new directory named the same as the profile that you want to create:# mkdir /etc/tuned/my-profile -
In the new directory, create a file named [filename]
tuned.conf. Add a[main]section and plug-in definitions in it, according to your requirements.For example, see the configuration of the
balancedprofile:[main] summary=General non-specialized TuneD profile [cpu] governor=conservative energy_perf_bias=normal [audio] timeout=10 [video] radeon_powersave=dpm-balanced, auto [scsi_host] alpm=med_power_with_dipm -
To activate the profile, use:
# tuned-adm profile my-profile -
Verify that the TuneD profile is active and the system settings are applied:
$ tuned-adm active Current active profile: my-profile$ tuned-adm verify Verification succeeded, current system settings match the preset profile. See TuneD log file ('/var/log/tuned/tuned.log') for details.
-
tuned.conf(5)man page
Modifying existing TuneD profiles
This procedure creates a modified child profile based on an existing TuneD profile.
-
The
tunedservice is running. See Installing and Enabling Tuned for details.
-
In the [filename]
/etc/tuned/directory, create a new directory named the same as the profile that you want to create:# mkdir /etc/tuned/modified-profile -
In the new directory, create a file named [filename]
tuned.conf, and set the[main]section as follows:[main] include=parent-profileReplace parent-profile with the name of the profile you are modifying.
-
Include your profile modifications.
Example 47. Lowering swappiness in the throughput-performance profileTo use the settings from the
throughput-performanceprofile and change the value ofvm.swappinessto 5, instead of the default 10, use:[main] include=throughput-performance [sysctl] vm.swappiness=5 -
To activate the profile, use:
# tuned-adm profile modified-profile -
Verify that the TuneD profile is active and the system settings are applied:
$ tuned-adm active Current active profile: my-profile$ tuned-adm verify Verification succeeded, current system settings match the preset profile. See TuneD log file ('/var/log/tuned/tuned.log') for details.
-
tuned.conf(5)man page
Setting the disk scheduler using TuneD
This procedure creates and enables a TuneD profile that sets a given disk scheduler for selected block devices. The setting persists across system reboots.
In the following commands and configuration, replace:
-
device with the name of the block device, for example
sdf -
selected-scheduler with the disk scheduler that you want to set for the device, for example
bfq
-
The
tunedservice is installed and enabled. For details, see https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/monitoring_and_managing_system_status_and_performance/getting-started-with-tuned_monitoring-and-managing-system-status-and-performance#installing-and-enabling-tuned_getting-started-with-tuned.
-
Optional: Select an existing TuneD profile on which your profile will be based. For a list of available profiles, see https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/monitoring_and_managing_system_status_and_performance/getting-started-with-tuned_monitoring-and-managing-system-status-and-performance#tuned-profiles-distributed-with-rhel_getting-started-with-tuned.
To see which profile is currently active, use:
$ tuned-adm active -
Create a new directory to hold your TuneD profile:
# mkdir /etc/tuned/my-profile -
Find the system unique identifier of the selected block device:
$ udevadm info --query=property --name=/dev/device | grep -E (WWN|SERIAL) ID_WWN=0x5002538d00000000_ ID_SERIAL=Generic-_SD_MMC_20120501030900000-0:0 ID_SERIAL_SHORT=20120501030900000NoteThe command in the this example will return all values identified as a World Wide Name (WWN) or serial number associated with the specified block device. Although it is preferred to use a WWN, the WWN is not always available for a given device and any values returned by the example command are acceptable to use as the device system unique ID.
-
Create the
/etc/tuned/_my-profile_/tuned.confconfiguration file. In the file, set the following options:-
Optional: Include an existing profile:
[main] include=existing-profile -
Set the selected disk scheduler for the device that matches the WWN identifier:
[disk] devices_udev_regex=IDNAME=device system unique id elevator=selected-schedulerHere:
-
Replace IDNAME with the name of the identifier being used (for example,
ID_WWN). -
Replace device system unique id with the value of the chosen identifier (for example,
0x5002538d00000000).To match multiple devices in the
devices_udev_regexoption, enclose the identifiers in parentheses and separate them with vertical bars:devices_udev_regex=(ID_WWN=0x5002538d00000000)|(ID_WWN=0x1234567800000000)
-
-
-
Enable your profile:
# tuned-adm profile my-profile
-
Verify that the TuneD profile is active and applied:
$ tuned-adm active Current active profile: my-profile$ tuned-adm verify Verification succeeded, current system settings match the preset profile. See TuneD log file ('/var/log/tuned/tuned.log') for details.
Related information
-
The
tuned.conf(5)man page -
The TuneD project website: https://tuned-project.org/