EMS Hardware Monitors: Overview

EMS Hardware Monitors: Glossary
The following terms are important for understanding hardware event monitors.
asynchronous event detection
The ability to detect an event at the time it occurs. When an event occurs the monitor is immediately
aware of it. This method provides quicker notification response than polling.
default monitoring requests
The default monitoring configuration created when the EMS Hardware Monitors are installed. The
default requests ensure that a complete level of protection is automatically provided for all supported
hardware resources.
Event Monitoring Service (EMS)
The application framework used for monitoring system resources on HP-UX 10.20 and 11.0.
Hardware monitoring uses the EMS framework for reporting events and creating PSM monitoring
requests. A collection of EMS system monitors are available at additional cost and are not included
with the hardware monitoring software. For more information on the EMS monitor, refer to Using
EMS HA Monitors, which can be downloaded from http://www.hp.com/go/hpux-ha-monitoring-
docs
event severity level
Each event that occurs within the hardware is assigned a severity level, which reflects the impact the
event may have on system operation. The severity levels provide the mechanism for directing event
notification. For example, you may choose a notification method for critical events that will alert
you immediately to their occurrence, and direct less important events to a log file for examination at
your convenience. Also, when used with MC/ServiceGuard to determine failover criteria, severe and
critical events cause failover.
hardware event
Any unusual or notable activity experienced by a hardware resource. For example, a disk drive that
is not responding, or a tape drive that does not have a tape loaded. When any such activity occurs,
the occurrence is reported as an event to the event monitor.
hardware event monitor
A monitor daemon that gathers information on the operational status of hardware resources. Each
monitor is responsible for watching a specific group or type of hardware resources. For example, the
tape monitor handles all tape devices on the system. The monitor may use polling or asynchronous
event detection for tracking events. Unlike a status monitor, an event monitor does not "remember"
the occurrence of an event. It simply detects and reports the event. An event can be converted into a
more permanent status condition using the Peripheral Status Monitor.
hardware resource
A hardware device used in system operation. Resources supported by hardware monitoring include
mass storage devices such as disks and tapes, connectivity devices such and hubs and multiplexors,
and device adapters.
MC/ServiceGuard
Hewlett-Packard's application for creating and managing high availability clusters of HP 9000
Series 800 computers. A high availability computer system allows application services to continue
in spite of a hardware or software failure. Hardware monitoring integrates with MC/ServiceGuard to
ensure that hardware problems are detected and reported immediately, allowing MC/ServiceGuard to
take the necessary action to maintain system availability. MC/ServiceGuard is available at additional
cost.
monitoring request
A group of settings that define how events for a specific monitor are handled by EMS. A monitoring
request identifies the severity levels of interest and the type of notification method to use when an
event occurs. A monitoring request is applied to each hardware device (or instance) supported by the
monitor. Monitoring requests are created for hardware events using the Hardware Monitoring
Request Manager. Monitoring requests are created for changes in hardware status using the EMS