Flow log storage space allocation
The Administration > Flow Log page Disk Allocation tab displays how NetProfiler disk storage is being used to store traffic flow information. The flow logs make it possible to quickly report on historical traffic flows with data resolutions of 1 minute, 5 minutes, 15 minutes, 1 hour, 6 hours, and 1 day. When viewing historical trends, you can use a lower data resolution to view a longer time span conveniently. When investigating specific behavior, you can use higher resolution for a higher degree of accuracy.
The tab displays the percent of total disk storage capacity that is allocated to the various flow logs. It also shows how long a period of time the flow data for each data resolution can be retained, using the current allocation, before being overwritten with newer data. By default, NetProfiler allocates approximately half its disk storage space to the highest resolution flow logs. It allocates the remaining disk space among the flow logs for the other data resolutions and to storing precomputed data (whether it is for preferred interfaces or general interface pre-compute).
You can modify the allocations. For example, if you do not anticipate wanting to run reports for time spans of more than 6 months, then you might want to reduce the allocation for the flow logs with 1-day data resolution and reallocate that space to the logs for 15-minute data resolution. This would allow NetProfiler to store a longer history of data with a 15-minute resolution.
For preferred interface data, the amount of space allocated along with the number of interfaces selected as "Preferred" determines the amount of historic preferred interface data that can be retained.
Caution on allocating zero disk space
If you set the disk space allocation for a data resolution interval to 0 GB or less than 0.1%, that data resolution will no longer be available for selection on the Report Criteria section of traffic reports. This is not user-reversible. It will require assistance from Riverbed Support to restore the log for that data resolution interval.
Additionally, if you set the disk space allocation for a 1-minute data resolution interval to less than 0.1%, it triggers a system restart, which may take the system down for tens of minutes, as well as require assistance from Riverbed Support to restore.
These considerations do not apply to the data storage allocation for precomputed interfacedata (either Interface Precompute or Preferred Interfaces). Changing this allocation from a non-zero number to zero causes all precomputed interface data to be deleted and stops storing any new precomputed data. However, you can subsequently allocate storage space for precomputed interfaces data and the data will start being stored again, without requiring assistance from Riverbed Support.