80 lines
3.1 KiB
Text
80 lines
3.1 KiB
Text
tuned: A simple daemon that performs monitoring and adaptive configuration
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of devices in the system
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Copyright (C) 2008, 2009 Red Hat, Inc.
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Authors: Phil Knirsch
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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How to use
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----------
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After installing the package you simply need to start the tuned
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service either with system-config-services or from the
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commandline in a rootshell via:
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service tuned start
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You can also automatically start it during system startup by
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switching it on via chkconfig:
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chkconfig tuned on
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After that the daemon will run automatically and monitor the
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usage of various system components. Based on that information
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components will then be put into lower or higher power saving
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modes to adapt to the current usage. Currently plugins for CPU,
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ethernet network and and ATA harddisk devices are implemented.
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The config file /etc/tuned.conf contains several sections in
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INI style. There is always a "main" section which controls
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overall options of the daemon. Currently only 1 option
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is available:
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interval: Interval for monitoring and tuning in seconds.
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Default is 10.
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Each monitoring and tuning plugin has an own section then.
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Currently only 1 option for plugins is available:
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enabled: Enabled or disable the plugin. Default is True.
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Any other value disables it.
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Monitoring/tuning plugins in detail
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-----------------------------------
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- CPU
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This plugin pair monitors the CPU usage of the system. If the current
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workload of it is very low (uptime smaller than 0.2) it will switch
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the system wide PM-QOS setting to 999 usec. If the load should get
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higher again the PM-QOS latency will be lowered to 100 again. More details
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about PM-QOS can be found here http://www.lesswatts.org/projects/power-qos/
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- Disk
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This plugin pair monitors usage of every disk in the system. For each
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harddisk we check how long they have been in idle mode. The longer they are
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the more we raise the power saving features for that drive and allow it to
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actually spin down. As soon as it is being used we then reduce the power
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savings for it and deactivate the automatic spin down again at higher
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performance levels again.
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- Net
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This plugin pair monitors usage of network devices. At startup it checks
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what speed the interfaces have. If at any time the utilization of any
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interface falls below 5% of the possible maximum speed we then renegotiate
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the speed of the interface at 100mbit. In case utilization goes up again
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we renegotiate to the full speed once more.
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