Recently I have been writing scripts to collect metrics from my environment and had set all collection levels to 2. However for metrics such as toalReadLatency, the data did not seem to collect until I changed it to level 3.
If I look at the counters in VMware's documention, the level of the totalReadLatency is of "2", but the Per Device Level is of "3". Why did I have to change the collection level to "3"?