There are two
NetScaler MIBs: the NetScaler software management MIB and the NetScaler IPMI
LOM hardware management MIB. The software management MIB is primarily used for
monitoring the application software and the application software's utilization
of hardware resources, such as CPU % and memory %. It provides a high level
view of the appliance and is therefore suitable for the application monitoring
function carried out by an application group within an organization. The LOM
MIB is used for monitoring the hardware health and therefore provides a lower
level view of the appliance, more applicable to the network monitoring function
carried out by a network monitoring group.
The LOM SNMP
traps in the LOM MIB report hardware failures. The NetScaler SNMP traps in the
NetScaler MIB report software failures and hardware load issues.
MIB has a very small subset of hardware sensors. It does not cover any BIOS
level failures, because the BIOS checks the hardware primarily during boot time
, before the NetScaler software starts. If the BIOS detects a failure, it does
not load the boot loader. If the boot loader does not load, the operating
system does not load, and therefore theNetScaler SNMP software service
responsible for sending the traps does not load.
Software Management MIB issues a warning under the following conditions only:
- If the failure is gradual
enough for the main CPU to issue an SNMP alert. An electrical failure close to
the CPU, such as a failed electrical capacitor, occurs too quickly for the CPU
to issue an alert.
- If the failure happens
after the BIOS, Operating System, and SNMP service have started and normal
boot-up has been successful.
- If the failure happens
while the operating system and other system software is in a stable enough
state for the SNMP software service to run.
NetScaler MIB is unable to report these warnings, because of hardware or
software failure, the LOM MIB monitors and reports the warnings. The LOM
microcontroller operates independently of the NetScaler software. To monitor
the hardware and software of the NetScaler appliance, you must use both the
NetScaler MIB and the LOM MIB.
IPMI LOM hardware management MIB SNMP firmware runs on the BMC microcontroller
chip. The BMC chip CPU sends a warning in the case of a hardware failure,
regardless of whether any of the above conditions occurs. For example, if the
BIOS halts the system during boot-up because of a memory DIMM failure, the BMC
chip uses the BIOS POST code snooping mechanism to detect the failure, and
sends a bad DIMM SNMP alert.
You can log on
to the LOM port to view the health information about the appliance. All system
sensor information, such as system temperature, CPU temperature, and status of
fans and power supplies, appears on the sensor readings page. The Event Log
records time stamps of routine events such as a power cycle, in addition to
recording hardware-failure events. If SNMP traps are enabled, these events can
be sent to your SNMP Network Monitoring software. For more information about
how to set up an SNMP alert, see Configuring SNMP Alerts.