.TH os_mon 7 "os_mon 2.2.9" "Ericsson AB" "Erlang Application Definition"
.SH NAME
os_mon \- OS Monitoring Application
.SH DESCRIPTION
.LP
The operating system monitor, OS_Mon, provides the following services:
.RS 2
.TP 2
*
\fBcpu_sup\fR\& CPU load and utilization supervision (Unix)
.LP
.TP 2
*
\fBdisksup\fR\& Disk supervision(Unix, Windows)
.LP
.TP 2
*
\fBmemsup\fR\& Memory supervision (Unix, Windows, VxWorks)
.LP
.TP 2
*
\fBos_sup\fR\& Interface to OS system messages (Solaris, Windows)
.LP
.RE

.LP
To simplify usage of OS_Mon on distributed Erlang systems, it is not considered an error trying to use a service at a node where it is not available (either because OS_Mon is not running, or because the service is not available for that OS, or because the service is not started)\&. Instead, a warning message is issued via \fIerror_logger\fR\& and a dummy value is returned, which one is specified in the man pages for the respective services\&.
.SH "CONFIGURATION"

.LP
When OS_Mon is started, by default all services available for the OS, except \fIos_sup\fR\&, are automatically started\&. This configuration can be changed using the following application configuration parameters:
.RS 2
.TP 2
.B
\fIstart_cpu_sup = bool()\fR\&:
Specifies if \fIcpu_sup\fR\& should be started\&. Defaults to \fItrue\fR\&\&.
.TP 2
.B
\fIstart_disksup = bool()\fR\&:
Specifies if \fIdisksup\fR\& should be started\&. Defaults to \fItrue\fR\&\&.
.TP 2
.B
\fIstart_memsup = bool()\fR\&:
Specifies if \fImemsup\fR\& should be started\&. Defaults to \fItrue\fR\&\&.
.TP 2
.B
\fIstart_os_sup = bool()\fR\&:
Specifies if \fIos_sup\fR\& should be started\&. Defaults to \fIfalse\fR\&\&.
.RE
.LP
Configuration parameters effecting the different OS_Mon services are described in the respective man pages\&.
.LP
See \fBconfig(5)\fR\& for information about how to change the value of configuration parameters\&.
.SH "SNMP MIBS"

.LP
The following MIBs are defined in OS_Mon:
.RS 2
.TP 2
.B
OTP-OS-MON-MIB:
This MIB contains objects for instrumentation of disk, memory and CPU usage of the nodes in the system\&.
.RE
.LP
The MIB is stored in the \fImibs\fR\& directory\&. It is defined in SNMPv2 SMI syntax\&. An SNMPv1 version of the MIB is delivered in the \fImibs/v1\fR\& directory\&.
.LP
The compiled MIB is located under \fIpriv/mibs\fR\&, and the generated \fI\&.hrl\fR\& file under the \fIinclude\fR\& directory\&. To compile a MIB that IMPORTS the \fIOTP-OS-MON-MIB\fR\&, give the option \fI{il, ["os_mon/priv/mibs"]}\fR\& to the MIB compiler\&.
.LP
If the MIB should be used in a system, it should be loaded into an agent with a call to \fIos_mon_mib:load(Agent)\fR\&, where \fIAgent\fR\& is the pid or registered name of an SNMP agent\&. Use \fIos_mon_mib:unload(Agent)\fR\& to unload the MIB\&. The implementation of this MIB uses Mnesia to store a cache with data needed, which implicates that Mnesia must be up and running\&. The MIB also use functions defined for the \fIOTP-MIB\fR\&, thus that MIB must be loaded as well\&.
.SH "SEE ALSO"

.LP
\fBcpu_sup(3erl)\fR\&, \fBdisksup(3erl)\fR\&, \fBmemsup(3erl)\fR\&, \fBos_sup(3erl)\fR\&, \fBnteventlog(3erl)\fR\&, \fBsnmp(3erl)\fR\&\&.