Using EMS HA Monitors

22 Chapter 1
Installing and Using EMS
Using EMS HA Monitors
How Do I Tell EMS When to Send Events?
While the monitor may be polling disks every 5 minutes, for example, you may only
want to be alerted when something happens that requires your attention. When you
create a request, you specify the conditions under which you receive an alert. Here
are the terms under which you can be notified:
If you select conditional notification, you may select one or more of these options:
When value is... You define the conditions under which you wish to be
notified for a particular resource using an operator (e.g. =,
not equal, >, >=, <, <=) and a value returned by the
monitor (e.g. UP, DOWN, INACTIVE). Text values are
mapped to numerical values. Specific values are in the
chapters describing the individual monitors.
When value changes This notification might be used for a resource that does
not change frequently, but you need to know each time it
does. For example, you would want notification each time
the number of mirrored copies of data changes from 2 to 1
and back to 2.
At each interval This sends notification at each polling interval. It would
most commonly be used for reminders or gathering data
for system analysis. Use this for only a small number of
resources at a time, and with long polling intervals of
several minutes or hours; there is a risk of affecting
system performance.
Initial Use this option as a baseline when monitoring resources such as
available filesystem space or system load. It can also be used to
test that events are being sent for a new request.
Repeat Use this option for urgent alerts. The Repeat option sends an
alert at each polling interval as long as the notify condition is
met. Use this option with caution; there is a risk of high CPU
use or filling log files and alert windows.
Return Use this option to track when emergency situations return to
normal.