From OpenNMS

Introduction

Data collection can range from the simple, to the moderately complex. Basic configuration is simple - in fact, the out of the box configuration will serve most situations well, and likely customisations are easy to make. More complex configurations are still possible, and advantage can be taken of features like SNMP tables.

Basic configuration

• Basic data collection howto

More complex configuration

SNMP tables

To collect data from SNMP tables which have arbitrary indexes (i.e. not just interface tables), for exampe, the hrStorageTable, you need to configure slightly differently. Details are here: Collecting SNMP data from tables with arbitrary indexes

Domain/IfAlias

If you need to separate your data storage by arbitrary "domains", and have better control of your data storage in an environment of distributed management and frequent adds, moves, and changes, then the "Domain/IfAlias" features are for you. See details here: Domain-IfAlias Data Storage How-To