Getting Started with TuneD on RHEL 8

Getting Started with TuneD on RHEL 8 demonstrates what the TuneD daemon is and how it can be used to optimize system performance.

So, what is the TuneD?

TuneD is a service/daemon that monitors your system and optimizes the performance under specific workloads. The core of TuneD are “profiles”, which tune your system for different use cases.

TuneD is distributed with many predefined profiles for use cases such as:

• High throughput
• Low latency
• Saving power

TuneD is a dynamic and static tuning tool that:

• Monitors system activity
• Applies predefined or custom tuning profiles
• Adjusts kernel parameters, CPU governors, disk I/O settings, and more

On RHEL 8, for instance, the TuneD is already installed and enabled by default:

systemctl status tuned

What Is It Used For?

TuneD helps system administrators:

• Improve performance for specific workloads (e.g., databases, virtual machines, network throughput)
• Reduce power consumption on idle or low-activity systems
• Automatically switch profiles based on system activity (dynamic tuning)

Common TuneD Profiles

A detailed analysis of a system can be very time-consuming. TuneD offers several predefined profiles for common use cases. You can also create, modify, and delete profiles.
Here are some of the most commonly used profiles:

Profile Name	Purpose
balanced	Balances performance and power saving
throughput-performance	Optimized for high disk and network throughput
latency-performance	Optimized for low latency; disables power-saving features
powersave	Minimizes power usage; may reduce performance
virtual-guest	Optimized for virtual machines
virtual-host	Optimized for virtualization hosts
desktop	Improves responsiveness for desktop environments
oracle	Tuned for Oracle database workloads (requires extra package)

Note: During system installation, the best profile for your system is automatically selected. Currently, the default profile is selected according to the following customizable rules:

Environment	Default profile	Goal
Compute nodes	throughput-performance	The best throughput performance
Virtual machines	virtual-guest	The best performance. If you are not interested in the best performance, you can change it to the balanced or powersave profile.
Other cases	balanced	Balanced performance and power consumption

Dynamic vs Static Tuning

• Static tuning: Applies settings once at startup or when switching profiles
• Dynamic tuning: Continuously monitors system activity and adjusts settings in real time

Dynamic tuning can be enabled in /etc/tuned/tuned-main.conf by setting:

dynamic_tuning = 1

How does dynamic tuning work?

• The tuneddaemon monitors system components, such as CPU, disk, and network usage.
• Based on activity levels, it adjusts system parameters to optimize performance or power efficiency.
• For example:
  • If disk I/O is high, consider increasing the throughput settings.
  • If the system is idle, it may reduce CPU frequency or disable unused devices to save power.

This enables the system to respond to changing workloads without requiring manual intervention.

How to Enable Dynamic Tuning?

1- Edit the main configuration file:

vi /etc/tuned/tuned-main.conf

2- Set the following option:

[main]
dynamic_tuning = 1
update_interval = 10  # Optional: interval in seconds between tuning updates

3- Restart the tuned service:

systemctl restart tuned

Notes:

• Dynamic tuning is disabled by default.
• It’s not recommended for performance-critical environments, such as databases or real-time systems, where static tuning may be more predictable.

Basic tune-adm Commands

We can use the program “tune-adm” to manage details of the TuneD daemon:

Command	Description
tuned-adm list	Lists all available tuning profiles
tuned-adm active	Shows the currently active profile
tuned-adm profile <name>	Activates the specified profile
tuned-adm off	Disables all tuning and stops the tuned daemon
tuned-adm recommend	Suggests the best profile for your system
tuned-adm verify	Verifies that the current profile is correctly applied
tuned-adm auto_profile	Enables automatic profile selection based on system characteristics
tuned-adm profile_info <name>	Displays detailed information about a specific profile

Let’s execute some commands to provide some examples.

1- List all available tuning profiles:

tuned-adm list

2- Shows the currently active profile:

tuned-adm active

3- Check the best profile for your system:

tuned-adm recommend

4- Get detailed information about a specific profile, for example, “hpc-compute”:

tuned-adm profile_info hpc-compute

5- Check if the current profile is correctly applied:

tuned-adm verify

Default Log File Location

/var/log/tuned/tuned.log

This log file contains:

• Profile activation history
• Dynamic tuning decisions
• Errors or warnings during profile application
• Debug information (if enabled)

You can increase the logging level for troubleshooting by starting tuned with the --debug option or modifying its configuration:

tuned -D

Or edit /etc/tuned/tuned-main.conf:

[main]
logging_level = DEBUG

Then restart the service to apply the new configuration:

systemctl restart tuned

That’s it for now 🙂