Calculate the size needed for your extended datastore

The extended datastore must have enough space to contain the amount of data generated by the ExtraHop system. The following procedure explains how you can calculate approximately how much free space you need for your extended datastore.

Before you begin

Familiarize yourself with ExtraHop datastore concepts.
In the following example, we show you how to calculate the amount of storage space required for 30 days worth of 5-minute metrics.
  1. Log in to the ExtraHop system through https://<extrahop-hostname-or-IP-address>.
  2. Click the System Settings icon, and then click System Health.
  3. Scroll down to the Data Feed section.
  4. In the Metric Data Lookback Estimates chart, note the Rate and Estimated Lookback for each metric cycle (or time period) that you want to store on the external datastore. The rate for 5-minute metrics in our example figure below is 55.4 KB/s.
  5. Calculate the amount of required space by applying the following formula: <rate> x <lookback_time>, and then convert the value to standard units.
    1. Convert the rate from seconds to days: 55.4 * 60 (seconds) * 60 (minutes) * 24 (hours) * 30 (days) = 143596800 KB for 30 days of lookback.
    2. Convert the rate from kilobytes to megabytes: 143596800 / 1024 = 140231 MB for 30 days of lookback.
    3. Convert the rate from megabytes to gigabytes:140231 / 1024 = 137 GB for 30 days of lookback.
    To store all of the 5 minute metrics from this appliance for 30 days, you need 137 GB of free space.
Published 2023-01-30