Tuned本质上是一个Linux环境中的后台进程，在运行过程中依据配置内容监控调整系统。监控程序会根据监控的配置内容，监控进程会持续监控结果反馈，调整优化策略。Ktune进程是在Red Hat 5.3引入的一项架构服务内容，为一些特定的用例场景来优化进程。
[root@SICS-MIGPC-DB ~]# ps -ef | grep tune
root 18878 18856 0 13:36 pts/0 00:00:00 grep tune
root 31656 1 0 Apr07 ? 00:00:00 /usr/bin/python /usr/sbin/tuned -d -c /etc/tuned.conf
tuned程序是后台运行的守护进程，-c参数用于指定当前的监控参数。
[root@SICS-MIGPC-DB tune-profiles]# cat /etc/tuned.conf
# disable tuned
[main]
[DiskMonitor]
enabled=False
[DiskTuning]
enabled=False
[NetMonitor]
enabled=False
[NetTuning]
enabled=False
[CPUMonitor]
enabled=False
[CPUTuning]
enabled=False
作为后台的进程tuned命令，是可以通过chkconfig和service命令进行配置启动的。
[root@SICS-MIGPC-DB ~]# service tuned status
tuned (pid 31656) is running...
tuned-adm命令是管理tuned组件的主要接口。
[root@SICS-MIGPC-DB ~]# tuned-adm help
Usage: tuned-adm <command>
commands:
help show this help message and exit
list list all available and active profiles
active show current active profile
off switch off all tuning
profile <profile-name> switch to given profile
通过list命令，可以查看当前应用和备选的所有Profile内容。
[root@SICS-MIGPC-DB ~]# tuned-adm list
Available profiles:
- laptop-battery-powersave
- virtual-guest
- enterprise-storage
- desktop-powersave
- default
- throughput-performance
- spindown-disk
- sap
- enterprise-storage-no-thp
- laptop-ac-powersave
- virtual-host
- server-powersave
- latency-performance
Current active profile: enterprise-storage-no-thp
通过tuned-adm命令的profile参数，可以保证系统动态的进行调整参数。
[root@SICS-MIGPC-DB tune-profiles]# tuned-adm profile desktop-powersave
Reverting to saved sysctl settings: [ OK ]
Calling '/etc/ktune.d/tunedadm.sh stop': [ OK ]
Reverting to cfq elevator: dm-0 dm-1 dm-2 sda [ OK ]
Stopping tuned: [ OK ]
Switching to profile 'desktop-powersave'
Applying ktune sysctl settings:
/etc/ktune.d/tunedadm.conf: [ OK ]
Calling '/etc/ktune.d/tunedadm.sh start': [ OK ]
Applying sysctl settings from /etc/sysctl.conf
Starting tuned: [ OK ]
从执行过程，可以看到系统不断的进行参数sysctl.conf调整应用。注意：/etc/tuned.conf内容也发生了变化。表明Profile的修改变化和Tuned行为变化。
[root@SICS-MIGPC-DB tune-profiles]# cat /etc/tuned.conf
#
# tuned configuration main service
#
[main]
# Interval for monitoring and tuning. Default is 10s.
# interval=10
#
# Disk monitoring section
#
[DiskMonitor]
# Enabled or disable the plugin. Default is True. Any other value
# disables it.
# enabled=False
#
# Disk tuning section
#
[DiskTuning]
# Enabled or disable the plugin. Default is True. Any other value
# disables it.
# enabled=False
# hdparm=False
# alpm=False
#
# Net monitoring section
#
[NetMonitor]
# Enabled or disable the plugin. Default is True. Any other value
# disables it.
# enabled=False
#
# Net tuning section
#
[NetTuning]
# Enabled or disable the plugin. Default is True. Any other value
# disables it.
# enabled=False
#
# CPU monitoring section
#
[CPUMonitor]
# Enabled or disable the plugin. Default is True. Any other value
# disables it.
# enabled=False
#
# CPU tuning section
#
[CPUTuning]
# Enabled or disable the plugin. Default is True. Any other value
# disables it.
# enabled=False
3、Profile内部信息
下面我们深入单个Profile的内部，探索一下内部的工作结构。在/etc/tune-profiles目录中，每个目录对应一个Profile内容。