The Firebox Memory graph in Fireware Web UI and WatchGuard Cloud, does not accurately reflect the total amount of available system memory on the Firebox. As a result it might indicate that a Firebox is low on memory when it is not.

To understand how much available memory your Firebox has, review these memory statistics in the Firebox System Manager Status Report:

• MemTotal — The total amount of memory available on your device.
• MemFree — The amount of memory that is not reserved or currently in use.  A low MemFree value does not indicate a problem with Firebox performance or resources.
• Buffers — The amount of memory the Firebox has reserved for temporary use by all Firebox processes.
• Cached — The amount of memory that is reserved by device processes, but not currently in use. A high Cached value does not indicate a memory problem.

The total available memory for a Firebox is the combined value of the MemFree, Cached, and Buffers statistics.

To improve system performance, Fireware allocates most available memory to buffers and the cache. If a process requires more memory, Fireware automatically frees up memory used by buffers and cache. 

The Memory graph shows the difference between the MemTotal and MemFree statistics. The Memory graph does not reflect the Cached and Buffers memory statistics. Because of this, high memory usage statistics on the Memory graph do not usually indicate a true low memory condition. 

To see a detailed breakdown of all memory usage statistics on the Firebox, look at the Status Report, available in Firebox System Manager. For more information about the Status Report, see Firebox System Manager Status Report Example in Fireware Help.