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man pages section 3: Extended Library Functions, Volume 1

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Updated: Wednesday, July 27, 2022
 
 

disksup (3erl)

Name

disksup - A Disk Supervisor Process

Synopsis

Please see following description for synopsis

Description

disksup(3)                 Erlang Module Definition                 disksup(3)



NAME
       disksup - A Disk Supervisor Process

DESCRIPTION
       disksup  is  a process which supervises the available disk space in the
       system. It is part of the OS_Mon application, see os_mon(6).  Available
       for Unix and Windows.

       Periodically  checks  the  disks. For each disk or partition which uses
       more  than  a  certain  amount  of  the  available  space,  the   alarm
       {{disk_almost_full, MountedOn}, []} is set.

         On Unix:
           All (locally) mounted disks are checked, including the swap disk if
           it is present.

         On WIN32:
           All logical drives of type "FIXED_DISK" are checked.

       Alarms are reported to the SASL alarm handler, see alarm_handler(3). To
       set  an  alarm, alarm_handler:set_alarm(Alarm) is called where Alarm is
       the alarm specified above.

       The alarms are cleared automatically when the alarm cause is no  longer
       valid.

CONFIGURATION
       The  following  configuration  parameters  can  be  used  to change the
       default values for time interval and threshold:

         disk_space_check_interval = int()>0:
           The time interval, in minutes, for the periodic disk  space  check.
           The default is 30 minutes.

         disk_almost_full_threshold = float():
           The threshold, as percentage of total disk space, for how much disk
           can be utilized before  the  disk_almost_full  alarm  is  set.  The
           default is 0.80 (80%).

         disksup_posix_only = bool():
           Specifies  whether the disksup helper process should only use POSIX
           conformant commands (true) or not. The default  is  false.  Setting
           this  parameter  to  true can be necessary on embedded systems with
           stripped-down versions of Unix tools like  df.  The  returned  disk
           data and alarms can be different when using this option.

           The  parameter  is  ignored  on  platforms that are known to not be
           POSIX compatible (Windows and SunOS).

       See config(4) for information about how to change the value of configu-
       ration parameters.

EXPORTS
       get_disk_data() -> [DiskData]

              Types:

                 DiskData = {Id, KByte, Capacity}
                  Id = string()
                  KByte = int()
                  Capacity = int()

              Returns the result of the latest disk check. Id is a string that
              identifies the disk or partition. KByte is the total size of the
              disk  or partition in kbytes. Capacity is the percentage of disk
              space used.

              The function is asynchronous in  the  sense  that  it  does  not
              invoke a disk check, but returns the latest available value.

              Returns [{"none",0,0}] if disksup is not available.

       get_check_interval() -> MS

              Types:

                 MS = int()

              Returns  the  time  interval,  in milliseconds, for the periodic
              disk space check.

       set_check_interval(Minutes) -> ok

              Types:

                 Minutes = int()>=1

              Changes the time interval, given in minutes,  for  the  periodic
              disk space check.

              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 Con-
              figuration above.

       get_almost_full_threshold() -> Percent

              Types:

                 Percent = int()

              Returns the threshold, in percent, for disk space utilization.

       set_almost_full_threshold(Float) -> ok

              Types:

                 Float = float(), 0=<Float=<1

              Changes the threshold, given as a float, for disk space utiliza-
              tion.

              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 Con-
              figuration above.

SEE ALSO
       alarm_handler(3), os_mon(3)



Ericsson AB                      os_mon 2.7.1                       disksup(3)