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  <header>
    <copyright>
      <year>1996</year><year>2016</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
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          http://www.apache.org/licenses/LICENSE-2.0

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      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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    </legalnotice>

    <title>disksup</title>
    <prepared></prepared>
    <docno></docno>
    <date></date>
    <rev></rev>
  </header>
  <module>disksup</module>
  <modulesummary>A Disk Supervisor Process</modulesummary>
  <description>
    <p><c>disksup</c> is a process which supervises the available disk
      space in the system. It is part of the OS_Mon application, see
      <seealso marker="os_mon_app">os_mon(6)</seealso>. Available for Unix
      and Windows.</p>
    <p>Periodically checks the disks. For each disk or partition which
      uses more than a certain amount of the available space, the alarm
      <c>{{disk_almost_full, MountedOn}, []}</c> is set.</p>
    <taglist>
      <tag>On Unix</tag>
      <item>
        <p>All (locally) mounted disks are checked, including the swap
          disk if it is present.</p>
      </item>
      <tag>On WIN32</tag>
      <item>
        <p>All logical drives of type "FIXED_DISK" are checked.</p>
      </item>
    </taglist>
    <p>Alarms are reported to the SASL alarm handler, see
      <seealso marker="sasl:alarm_handler">alarm_handler(3)</seealso>.
      To set an alarm, <c>alarm_handler:set_alarm(Alarm)</c> is called
      where <c>Alarm</c> is the alarm specified above.</p>
    <p>The alarms are cleared automatically when the alarm cause is no
      longer valid.</p>
  </description>

  <section>
    <marker id="config"></marker>
    <title>Configuration</title>
    <p>The following configuration parameters can be used to change
      the default values for time interval and threshold:</p>
    <taglist>
      <tag><c>disk_space_check_interval = int()>0</c></tag>
      <item>
        <p>The time interval, in minutes, for the periodic disk space
          check. The default is 30 minutes.</p>
      </item>
      <tag><c>disk_almost_full_threshold = float()</c></tag>
      <item>
        <p>The threshold, as percentage of total disk space, for how
          much disk can be utilized before the <c>disk_almost_full</c>
          alarm is set. The default is 0.80 (80%).</p>
      </item>
      <tag><c>disksup_posix_only = bool()</c></tag>
      <item>
        <p>Specifies whether the <c>disksup</c> helper process should only
          use POSIX conformant commands (<c>true</c>) or not. The default is
          <c>false</c>. Setting this parameter to <c>true</c> can be
          necessary on embedded systems with stripped-down versions
          of Unix tools like <c>df</c>. The returned disk data and alarms
          can be different when using this option.</p>
        <p>The parameter is ignored on platforms that are known to not be
          posix compatible (Windows and SunOS).</p>
      </item>
    </taglist>
    <p>See <seealso marker="kernel:config">config(4)</seealso> for
      information about how to change the value of configuration
      parameters.</p>
  </section>
  <funcs>
    <func>
      <name>get_disk_data() -> [DiskData]</name>
      <fsummary>Get data for the disks in the system</fsummary>
      <type>
        <v>DiskData = {Id, KByte, Capacity}</v>
        <v>&nbsp;Id = string()</v>
        <v>&nbsp;KByte = int()</v>
        <v>&nbsp;Capacity = int()</v>
      </type>
      <desc>
        <p>Returns the result of the latest disk check. <c>Id</c> is a
          string that identifies the disk or partition. <c>KByte</c> is
          the total size of the disk or partition in kbytes.
          <c>Capacity</c> is the percentage of disk space used.</p>
        <p>The function is asynchronous in the sense that it does not
          invoke a disk check, but returns the latest available value.</p>
        <p>Returns <c>[{"none",0,0}]</c> if <c>disksup</c> is not
          available.</p>
      </desc>
    </func>
    <func>
      <name>get_check_interval() -> MS</name>
      <fsummary>Get time interval, in milliseconds, for the periodic disk space check</fsummary>
      <type>
        <v>MS = int()</v>
      </type>
      <desc>
        <p>Returns the time interval, in milliseconds, for the periodic
          disk space check.</p>
      </desc>
    </func>
    <func>
      <name>set_check_interval(Minutes) -> ok</name>
      <fsummary>Set time interval, in minutes, for the periodic disk space check</fsummary>
      <type>
        <v>Minutes = int()>=1</v>
      </type>
      <desc>
        <p>Changes the time interval, given in minutes, for the periodic
          disk space check.</p>
        <p>The change will take effect after the next disk space check
          and is non-persist. That is, in case of a process restart,
          this value is forgotten and the default value will be used.
          See <seealso marker="#config">Configuration</seealso> above.</p>
      </desc>
    </func>
    <func>
      <name>get_almost_full_threshold() -> Percent</name>
      <fsummary>Get threshold, in percent, for disk space utilization</fsummary>
      <type>
        <v>Percent = int()</v>
      </type>
      <desc>
        <p>Returns the threshold, in percent, for disk space utilization.</p>
      </desc>
    </func>
    <func>
      <name>set_almost_full_threshold(Float) -> ok</name>
      <fsummary>Set threshold, as percentage represented by a float, for disk space utilization</fsummary>
      <type>
        <v>Float = float(), 0=&lt;Float=&lt;1</v>
      </type>
      <desc>
        <p>Changes the threshold, given as a float, for disk space
          utilization.</p>
        <p>The change will take effect during the next disk space check
          and is non-persist. That is, in case of a process restart,
          this value is forgotten and the default value will be used.
          See <seealso marker="#config">Configuration</seealso> above.</p>
      </desc>
    </func>
  </funcs>

  <section>
    <title>See Also</title>
    <p><seealso marker="sasl:alarm_handler">alarm_handler(3)</seealso>,
      <seealso marker="os_mon_app">os_mon(3)</seealso></p>
  </section>
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