A Disk Supervisor Process
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.
All (locally) mounted disks are checked, including the swap disk if it is present.
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The alarms are cleared automatically when the alarm cause is no longer valid.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 configuration parameters.
Functions
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.
MS = int()
Returns the time interval, in milliseconds, for the periodic disk space check.
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 Configuration above.
Percent = int()
Returns the threshold, in percent, for disk space utilization.
Float = float(), 0=<Float=<1
Changes the threshold, given as a float, for disk space utilization.
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 Configuration above.