9.3 Manage Tuning Profiles

9.3 Manage Tuning Profiles

Quick Answer: Use tuned-adm to manage Tuned profiles on RHEL 10. tuned-adm list shows profiles, tuned-adm active shows the current one, and tuned-adm profile <name> applies a profile. Confirm with tuned-adm active. This is system-wide performance/latency tuning—not the same as renice on one process.

Official skill and exam intent

Under Operate running systems, EX200 expects you to manage tuning profiles. On Red Hat Enterprise Linux, that means the Tuned daemon and the tuned-adm CLI: list profiles, see which is active, switch profiles, and leave the system in the requested state after reboot (with Tuned still applying that profile).

Example task language:

• “Configure the system to use the throughput-performance tuning profile.”
• “Show the active tuned profile and set it to virtual-guest.”
• “Ensure the recommended profile is applied.”

Graders check active profile (and that Tuned is working), not whether you recompiled a kernel.

What Tuned does

Tuned is a profile-based system tuning service. A profile is a named collection of settings that may adjust:

• Kernel sysctl parameters
• Disk I/O scheduler hints
• CPU frequency/power related settings
• Other plug-in managed resources (network, audio, etc. depending on profile)

Profiles live as directories under /usr/lib/tuned/ (shipped) and optionally /etc/tuned/ (local customizations). You rarely hand-edit them on EX200—you select a provided profile with tuned-adm.

Service readiness

If tuned-adm errors because the daemon is down:

systemctl status tuned
sudo systemctl enable --now tuned
# or
sudo systemctl start tuned

On a normal RHEL server image, tuned is often installed and enabled. If a minimal lab removed it, install the package (package name typically tuned) with DNF when the task implies Tuned must work—only if repositories allow and the task is about profiles.

rpm -q tuned
systemctl is-enabled tuned
systemctl is-active tuned

Exam persistence: For a profile to still apply after reboot, the tuned service should be enabled and the selected profile stored as active. tuned-adm profile NAME both switches the profile and records it for Tuned to re-apply.

Core tuned-adm commands

List profiles

tuned-adm list

Output includes available profile names and usually marks the active profile. Read the list carefully—spelling must match exactly when you switch.

Show active profile

tuned-adm active

Example:

Current active profile: balanced

This is your primary verification command after any change.

Apply a profile

sudo tuned-adm profile throughput-performance
sudo tuned-adm profile latency-performance
sudo tuned-adm profile virtual-guest
sudo tuned-adm profile balanced
sudo tuned-adm profile desktop

Then immediately:

tuned-adm active

Recommended profile

tuned-adm recommend
# Apply whatever Tuned recommends for this system:
sudo tuned-adm profile $(tuned-adm recommend)
# Or on some versions there is a direct path—prefer explicit profile name if the task names one

If the task says “use the recommended profile,” run tuned-adm recommend, then tuned-adm profile with that exact string, then tuned-adm active.

Turn tuning off

sudo tuned-adm off
tuned-adm active

off disables profile application (active may report that no profile is active / tuning is off—read the message). Only use when the task asks to disable Tuned profiling—not as a casual “reset.”

Verify operation (optional detail)

tuned-adm verify

Reports whether the system settings still match the active profile (useful if something manually changed sysctls afterward). Not always required for credit, but good diagnostics.

Common profile names (recognition set)

Exact sets depend on installed tuned profile packages. Know these names by sight:

Exam rule: Use the exact profile string from the task or from tuned-adm list. Do not “upgrade” the request to a profile you like better.

Profiles vs nice vs kill

A throughput profile does not stop a runaway binary. Renicing make does not replace a required latency-performance profile. Keep the tools in their lanes.

Files and customization (awareness only)

ls /usr/lib/tuned/
ls /etc/tuned/
cat /etc/tuned/active_profile    # often reflects active name; prefer tuned-adm active

Custom profiles can be created under /etc/tuned/ for real admin work. EX200 almost always asks you to activate a shipped profile, not author a new one. If you see active_profile or profile_mode files, treat tuned-adm as the supported interface so the daemon stays consistent.

End-to-end exam scenarios

Scenario A — Set a named profile

Task: Configure the system to use throughput-performance.

systemctl is-active tuned || sudo systemctl enable --now tuned
tuned-adm list
sudo tuned-adm profile throughput-performance
tuned-adm active
# Expect: Current active profile: throughput-performance

Optional reboot check in practice:

sudo reboot
# after login:
tuned-adm active
systemctl is-enabled tuned

Scenario B — Recommended profile

tuned-adm recommend
# e.g. virtual-guest
sudo tuned-adm profile virtual-guest
tuned-adm active

Scenario C — Confirm before changing

Tasks sometimes only ask what is active, or to change only if wrong:

tuned-adm active
# If already correct, do not churn. If wrong, switch and re-check.

Scenario D — Tuned not running

tuned-adm active
# Error contacting tuned daemon...
sudo systemctl enable --now tuned
sudo tuned-adm profile balanced
tuned-adm active

Troubleshooting map

Common traps

1. Typo in profile name — throughput_performance vs throughput-performance (hyphen).
2. Changing profile without Tuned running — start/enable the service first.
3. Assuming tuned-adm profile is temporary — it is the supported persistent selection for Tuned; still ensure the service is enabled for reboot.
4. Using renice to “satisfy” a tuning-profile task — wrong tool; graders check tuned-adm active.
5. Editing random sysctls by hand then forgetting Tuned may overwrite them when the profile reapplies.
6. tuned-adm off by accident — re-apply the required profile.

RHEL 10 notes

Tuned remains the Red Hat-supported profile mechanism on RHEL 10 for this objective. Command names tuned-adm list, active, and profile are the ones to drill until muscle memory. Combine with earlier process skills: if the system is under load, you may still need top/kill/renice for a bad user process and a correct Tuned profile for system policy—they stack, they do not substitute.

Section checkpoint

You should ensure tuned is running, list profiles, read the active profile, apply the exact profile the task requires (or the recommended one), verify with tuned-adm active, and understand that this configuration is system-wide and meant to survive reboot when the service is enabled. Together with process identification, kill signals, and nice/renice, that completes the process-and-tuning slice of Operate running systems for EX200.