1.yum install tuned tuned-utils
2. tuned-adm profile virtual-guest
3. dd if=/dev/zero of=tmpfile bs=1M count=1000
See the tables below :
Profile explanation :
default
The default power-saving profile. This is the most basic power-saving profile. It enables only the disk and CPU plug-ins. Note that this is not the same as turning tuned-adm off, where both tuned and ktune are disabled.
latency-performance
A server profile for typical latency performance tuning. It disables tuned and ktune power-saving mechanisms. The cpuspeed mode changes to performance. The I/O elevator is changed to deadline for each device. For power management quality of service, cpu_dma_latency requirement value 0 is registered.
throughput-performance
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 latency-performance, except:
kernel.sched_min_granularity_ns (scheduler minimal preemption granularity) is set to 10 milliseconds,
kernel.sched_wakeup_granularity_ns (scheduler wake-up granularity) is set to 15 milliseconds,
vm.dirty_ratio (virtual machine dirty ratio) is set to 40%, and
transparent huge pages are enabled.
enterprise-storage
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 throughput-performance profile, with one addition: file systems are re-mounted with barrier=0.
virtual-guest
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 throughput-performance profile, except:
readahead value is set to 4x, and
non root/boot file systems are re-mounted with barrier=0.
virtual-host
Based on the enterprise-storage profile, virtual-host also decreases the swappiness of virtual memory and enables more aggressive writeback of dirty pages. This profile is available in Red Hat Enterprise Linux 6.3 and later, and is the recommended profile for virtualization hosts, including both KVM and Red Hat Enterprise Virtualization hosts.
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