vSphere 5: Memory share calculation for mem.minfreepct
This section on memory share which has been changed in vSphere 5 which is also written in Frank Denneman, Mem.MinFreePct sliding scale function.
The example is as below:
Let’s use an example to explore the savings of the sliding scale technique. On a server configured with 96GB RAM, the MinFreePct threshold will be set at 1597.6MB, opposed to 5898.24MB if 6% was used for the complete range 96GB.
|Free memory state||Threshold||Range||Result|
|Total High Threshold||1597.60MB|
I was trying to get the calculation for the Result column and thought to elaborate it on a clearer picture which a believe some are confused like myself.
The first 0-4GB will be on 6%, followed by from 4GB-8GB will be 4%(which is total of 4GB), then the next 12GB-28GB on 2% (which is 16GB) and lastly the remaining memory minus off from total on 1% (which is 68GB). When you add those up would give you the Threshold.
Hope that helps how the math was derived.