This is a gauge reporting the highest number of data buffers that have been in use on this node since the last reset, applicable across all platforms. This peak figure is what an admin uses to size the node's total buffer pool appropriately; a peak that regularly approaches the pool's total capacity is the trigger to investigate whether more buffer memory can be allocated or traffic needs to be reduced or redistributed. For example, a peak of 495 buffers in use against a 500-buffer total pool size would indicate the node came within 1% of exhausting its data buffers at some point since the last reset.