1. Home
  2. Data Retention

Data Retention

Performance (Time-series) Data

OmniCenter stores performance-type-data (the sort of data you would typically see in a graph) in a format called a “round-robin database” using the open-source RRDTool.

At the time a device is first polled, the data polling engine in OmniCenter creates a round-robin database file for each data type being collected. The format of this file is such that it does not grow in file size as new data is added. Instead, it “rolls up” older data by condensing it into averages of itself, freeing up space for the more granular recent data. This creates a way to manage storage in a scalable way.

As a result, OmniCenter can retain data for 3 years. However, as you go farther back in time, the data becomes less granular and more averaged.


“Peak” data is rolled-up and stored separately from “averaged” data using a MAX function. This prevents historical peaks from being blunted over time.

By default, OmniCenter retains data for the following intervals:



OmniCenter always provides the most granular data available that covers the entire time of the report. Therefore a report run in OmniCenter with a start date of 120 days ago will show data from the 30-minute average. Zooming into a graph will show the most granular data available for the zoomed time period, allowing you to quickly get to the most granular data level available.

Log-based Data

For historical-log-type data (such as syslog, alert history, audit logs, detailed call records, and the like) OmniCenter will store the last 3 million records, regardless of date. Each log type is handled independently, so OmniCenter stores 3 million of each type (except SNMP trap and syslog—which are stored together). In most environments, this provides several years of log history. However, in very-high-traffic environments, it may be less. OmniCenter also stores time-series data (stored as detailed above) for log monitoring features.

Flow-based Data

Flow-based data is accounting type data on specific IP connections, such as that provided by NetFlow, J-Flow, sFlow and IPFIX. OmniCenter stores this data in a few ways: as detailed 1-minute flow log data, which includes specific information on individual TCP connections (flows) between devices, which is stored for 6 hours; and as hourly conversation summaries, which are stored for 7 days. Statistical data (overall volume per application per interface) are stored as indicated in the time-series data table above for a maximum of three years.

Please contact Netreo Support to discuss your requirements if you need additional detailed history storage. Some environments may require additional hard disk storage to accommodate larger flow archives.