If disk filesystem min%|minspace is set then the snmp agent will report information about that filesystem via the .1.3.6.1.4.1.2021.9 (enterprises.ucdavis.dskTable.dskEntry) OID. If you define a minimum free space size (or percentage) and the free space falls below that then .1.3.6.1.4.1.2021.9.1.100.X will be set to 1 and an error message set in .1.3.6.1.4.1.2021.9.1.101.X (where X indicates the order of the disk definition).
So for the snmp object we can now define @disks filesys_$ size_$ percent_$ if both percent and size are defined for a filesystem obj_snmp will default to percent.
the pass directive allows the agent to hand off control of a branch of the OID tree to a script or program. The parameters are OID executable and arguements
pass .1.3.6.1.4.1.2021.255 /bin/sh /usr/local/sbin/cputemp |
In LCFG this becomes.
+snmp.passes i2c
+snmp.oid_i2c .1.3.6.1.4.1.2021.255
+snmp.command_i2c /bin/sh /usr/local/sbin/cputemp |
Once you have got this all up and running there are a number of tools which can be used to gether the information (snmpget/walk,
tkined,
rrdtool) I've used NRG (largely becuase I've used it before).