tuned is a daemon that monitors your system and applies a collection of kernel parameters, sysctl settings, I/O scheduler tweaks, and CPU governor policies bundled into a profile. Instead of hand-tuning dozens of /proc and /sys knobs, you pick one profile that matches your workload (database server, virtual guest, power saving, etc.) and tuned sets everything at once. The tuned-adm CLI is how you list, activate, query, and deactivate profiles. On the RHCSA exam, you may be asked to set a specific tuning profile and verify it persists across reboots -- the pattern is always tuned-adm profile <name> followed by tuned-adm active to confirm.
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