By user9148476 on Apr 07, 2009
For the purposes of this discussion, I'll refer to an SNMP trap from Solaris FMA as an "FMA SNMP trap" and one from ILOM as an "ILOM SNMP trap".
The key to understanding why both ILOM and Solaris must be monitored is the flow of fault information in the system. This picture (admittedly simplified) should help:
For faults generated in their respective precinct, ILOM diagnosed faults will produce an ILOM SNMP trap. And Solaris FMA faults will produce an FMA SNMP trap (via the snmp-trapgen plugin). And there's a level of fault sharing between ILOM and Solaris - but notice the flow of fault information is from Solaris to ILOM.
In Solaris, an FMD plugin called the Event Transport Module (ETM) subscribes to selected fault events and (you guessed it) transports them to ILOM. ILOM then updates its state and view of the components in the system. And for faults received from Solaris, ILOM will also generate an SNMP trap. However, ETM does not transport all fault events. Some fault events are not meaningful to ILOM as they represent components beyond ILOM's visibility. Precisely which faults are forwarded by ETM is driven by a configuration file, etm.conf, tailored for each platform or platform family.
This gives us a few flows for SNMP trap generation.
- FMA diagnosed fault that is transported to ILOM: snmp-trapgen in Solaris generates an FMA SNMP trap. And ILOM generates an ILOM SNMP trap when the fault is received in the service processor.
- FMA diagnosed fault that is not transported to ILOM: snmp-trapgen in Solaris generates an FMA SNMP trap.
- ILOM diagnosed fault: ILOM generates an ILOM SNMP trap
- ILOM chassis event: ILOM generates an ILOM SNMP trap
Summing this up, taking into account the faults that ETM will forward to ILOM, we can expect the following SNMP trap generation for the various subsystems:
|Subsystem||FMA SNMP Trap||ILOM SNMP Trap|
|ASR Disables||no||yes||Component Insertion/Removal||no||yes|
|1 T5440 and derivatives only|
As I'm not an expert on ILOM, the table above may not be an exhaustive list of all of the ILOM events that can trigger an ILOM SNMP trap. But I believe it's sufficient to illustrate the point that if you're monitoring your SPARC CMT systems via SNMP, you must monitor both ILOM SNMP and FMA SNMP traps.