Disk space requirements for OMEGAMON for z/OS historical data tables

The installation documentation for your OMEGAMON products provides the basic space requirements for the Tivoli Enterprise Monitoring Server, Tivoli Enterprise Portal, the Tivoli Enterprise Portal Server, and the monitoring agents themselves. These basic space requirements do not include the additional space that is required for maintaining historical data files.

The Tivoli Enterprise Portal displays two kinds of history data: short-term and long-term. Short-term history data, up to 24 hours worth, is retrieved from local storage on the host of the monitoring agent or the monitoring server to which it reports. Any data older than 24 hours is retrieved from the Tivoli® Data Warehouse. Ideally, then, you want to allocate enough space for 24 hours of short-term historical data at the location of the persistent data store.

The OMEGAMON enhanced 3270 user interface displays near-term history data. Near-term history data is retrieved from either the same local storage on the host of the monitoring agent or the monitoring server to which it reports or from the monitoring agent. Depending on the capacity of the local storage or the monitoring agent, there might be several days of near-term history available to display.

Because of the variations in client distributed systems, system size, number of managed systems, sampling intervals, and so on, it is difficult to provide actual additional disk space requirements for historical data collection. You must experiment to determine how much space you need.

Use the default amounts to configure the data store initially, then observe how quickly space gets used. Eventually, you want to allocate enough space so that maintenance procedures only need to run once a day. The information in this appendix is provided to help you determine how much space is required.