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 beginFamiliarize yourself with ExtraHop datastore concepts.
- Log in to the ExtraHop system through https://<extrahop-hostname-or-IP-address>.
- Click the System Settings icon, and then click System Health.
- Scroll down to the Data Feed section.
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.
Calculate the amount of required space by applying the following formula:
<rate> x <lookback_time>, and then convert the value
to standard units.
To store all of the 5 minute metrics from this appliance for 30 days, you need 137 GB of free space.
- Convert the rate from seconds to days: 55.4 * 60 (seconds) * 60 (minutes) * 24 (hours) * 30 (days) = 143596800 KB for 30 days of lookback.
- Convert the rate from kilobytes to megabytes: 143596800 / 1024 = 140231 MB for 30 days of lookback.
- Convert the rate from megabytes to gigabytes:140231 / 1024 = 137 GB for 30 days of lookback.
Next stepsConfigure an extended CIFS or NFS datastore.