Memory extension

Firmware version >= 3.3 allows to store some old statistical data on attached flash based storage device to extend the amount of time for historical data. When enabled, the system will automatically swap out old history data onto the flash device making more room in the main memory for total increased history data.

This is a BETA feature which is subject to change in future firmware versions. It is only recommended to be used for very fast flash based storage devices and devices with low load.

The configuration dialog allows to check the speed of the active storage device.

  • Excellent performance: this result can only be reached on very fast U.2 or PCIe flash devices, such as Intel Optane storage. This class of devices can be used for low to medium traffic load.
  • Acceptable performance: this result can be reached by fast U.2 or SATA flash devices. It can be used for low traffic load.
  • Low performance: the speed is usually too slow to be used effectively for this feature. In very low traffic load situations it might still be usable.

Spinning hard disc drives are in general not recommended to be used for this feature.

The configuration dialog allows to choose a size of the memory extension. Larger values does not automatically increase the history time, as only part of the historical data ca be swapped out. As long as the usage is not reaching 100%, there is no need to increase the memory extension.

Recommended size values:

  • Use at least 1 GB of memory.
  • If possible use 1-2 times the amount of main memory.

Saving the settings will activate the memory extension immediately.

To disable the memory extension, first disable the feature and then restart the packet processing in the administration menu.

Note: The storage device cannot be deactivated as long as the memory extension is enabled.

Tip: Since only data that is no longer changing can be swapped out onto the storage device, the graph detail settings can be adjusted to make more information available for external memory. The graph resolution reduction can be adjusted to lower values. It will however also make showing graph data slower for larger time periods so the best value depends on the actual amount of data stored and the use case. It is possible to start with a value of 1/1 for the reduction parameter and increase it, if the overall performance is not good enough.

Recommended SSD devices

We recommend to use sever-grade high speed SSDs with low access times and high I/O ops.

Speed Model Notes
High Intel Optane SSD DC P5800X series Recommended for low to medium traffic load, statistic output is slower than usual
Average Micron 9300 MAX SSD Use for low traffic load only, statistic output is slower too
Low Other U.2/SATA/USB SSDs might be used for low traffic scenarios, access to statistics will be significantly slower as well