7.2. Profiles for file system performance
The tuned-adm tool allows users to easily swap between a number of profiles that have been designed to enhance performance for specific use cases. The profiles that are particularly useful in improving storage performance are:
- A server profile for typical latency performance tuning. It disables tuned and ktune power-saving mechanisms. The
cpuspeedmode changes to
performance. The I/O elevator is changed to
deadlinefor each device. The
cpu_dma_latencyparameter is registered with a value of
1(the lowest possible latency) for power management quality-of-service to limit latency where possible.
- A server profile for typical throughput performance tuning. This profile is recommended if the system does not have enterprise-class storage. It is the same as
kernel.sched_min_granularity_ns(scheduler minimal preemption granularity) is set to
kernel.sched_wakeup_granularity_ns(scheduler wake-up granularity) is set to
vm.dirty_ratio(virtual memory dirty ratio) is set to 40%, and
- transparent huge pages are enabled.
- This profile is recommended for enterprise-sized server configurations with enterprise-class storage, including battery-backed controller cache protection and management of on-disk cache. It is the same as the
readaheadvalue is set to
- non root/boot file systems are re-mounted with
More information about tuned-adm is available on the man page (
man tuned-adm), or in the Power Management Guide available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.