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6. Notes about Platforms

Standartized MIBs provide some information about an agent. The more interesting stuff, especially when it comes to hardware monitoring, is usually available only through vendor specific MIBs.

The degree to which details are available vary strongly. Some agents only return “The physical hard drive in bay 5 is OK.” while others return details up to “The drive's LED will be blinking for another 1.5 seconds.”

6.1. Brocade

If you have a SAN switch from Hewlett-Packard, then you might want to check if there is a Brocade device underneath.

nagios@host>snmpwalk -v 2c -c COMMUNITY -On IP \
> SNMPv2-MIB::sysObjectID.0

If the result contains “.” then you are lucky.

One remarkable thing about those SAN switches is that as far as SNMP is concerned, fans, power supply units and temperature sensors are all the same—“sensors”. Together they form one table but for the sake of performance logging they are treated separately. Sharing one table is also the reason why the plugins to check those entities report “weired” indices.

6.2. Cisco

Cisco has developed a staggering amount of MIBs and their SNMP agents provide detailed information about just about every aspect of the devices operation.

The plugins should work with Catalyst OS as well as IOS. Some also work with PIX Security Appliances.

Note: It seems that Cisco PIXes support only SNMP version 1.

The cisco_vpn plugins are designed to work with the Cisco VPN Concentrator. I do not have access to a Concentrator any longer so these plugins are partially supported at best.

6.3. Compaq

Compaq (now Hewlett-Packard) provides SNMP agents for their ProLiant Servers1 which provide very detailed information about those machines.

So far I have not figured out a way to monitor a HP StorageWorks Enterprise Virtual Array (except the Storage Management Appliance, that is).

6.4. Microsoft Windows

The SNMP agent of Microsoft Windows Server 2003 does not report cpu or memory usages. However there is a free (as in beer) version of “SNMP Informant2 by Garth K. Williams which can be used to query these.

6.5. Network Appliance

Network Appliance devices provide the highest number of values seen so far. Nevertheless they report only abstract values when it comes to hardware details, e. g. “There are no failed fans”.

Most remarkable however is the lack of support for SNMP Version 2c. The plugins have to be called with the parameter “-1”.

6.6. Net-SNMP and lm_sensors

A wide range of computers uses lm_sensors3 to monitor temperatures, voltages and fans. Net-SNMP provides access to lm_sensors data if it has been compiled with lm_sensors support.

There is however a catch: No thresholds are provided and reference values are only given as names. Therefor it takes some fiddling to set up these plugins.

6.7. Uninterruptable Power Supplies

Uninterruptable Power Supplies are of course not a vendor, but they use a standard4 MIB and plugins were grouped like those of a vendor.

It depends on the device if and to what extend values are returned. It is even possible that inconsistent values are returned. For instance an UPS might return output voltage, current and power each 0, but an output load greater than 0.

So you will have to figure out yourself how far you can trust the performance data. Alarms and outputs (as in check_ups_outputs) should always work.

1That is, the plugins were only tested with ProLiants, others might work as well and feedback would be welcome.




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