Users Guide

Monitoring Network Availability | Performance Monitoring
376 OMNM 6.5.3 User Guide
Retention Policies
The basis of all reporting and dashboard presentations is data retained from monitors. In other
words, each monitor provides a simple schema from which you can produce a chart, graph or
report.
All monitors rely on a polling engine which executes device interactions at regular intervals. To
reduce resource impacts, you can exclude some of the collected data from what OpenManage
Network Manager retains. A monitor could even have no retained data, only emitting events based
on transient results in the execution/calculation. Another example: the application can derive a
metric from several collected values and you may opt to retain only the derived result. Monitors
may share a retention policy.
OpenManage Network Manager rolls up data hourly and daily into aggregations. See the
Aggregate
Data
on page 377 for more details. The retention policy controls how long OpenManage Network
Manager holds data per aggregation period. You must select the correct period if you want to review
what has been collected.
When you select
Manage Retention Policies in the Monitors portlet, first a list of available policies
appears. Clicking the
Add button at the top of the screen lets you create a new policy, while clicking
the
Edit button to the right of selected, listed policies lets you modify existing policies. The Delete
button to the right of listed policies removes them from the list.
Editor
Monitors may share a retention policy. The retention policy controls how long data is held per roll-
up period. The editor for Retention policies lets you assign characteristics and monitors to them.
The editor contains the following fields: