For one of our SQL Server, we recently add more memory. The initial value was 12GB. The server experienced a lack of physical memory so we added another 12GB, for a total of 24GB. Then I have set the followings values : min. server memory 1024MB - max server memory : 19456. Well everything is running fine, but I have few questions about SQL Server memory usage. Indeed, SQL server suddenly used all the assigned memory : 

[![enter image description here](https://i.stack.imgur.com/im2Um.jpg)](https://i.stack.imgur.com/im2Um.jpg)

I have a good book which say :"Once memory usage has increased beyond the min server memory setting, SQL Server won't release any memory below that amount" - Is the same thing happening here with max server memory ?

[![enter image description here](https://i.stack.imgur.com/fuSwo.jpg)](https://i.stack.imgur.com/fuSwo.jpg)

I'm wondering (again) how to measure how much memory SQL is really using. I'm confused with the parameter "*Total server memory (KB)*" ("this counter measures SQL Server's total buffer pool usage"). According perfmon it is only 2MB :

[![enter image description here](https://i.stack.imgur.com/TwFIp.jpg)](https://i.stack.imgur.com/TwFIp.jpg)

Maybe we could spare the ESX some RAM and SQL Server memory (i.e PLE) will still show good values - How to be sure ? A good explanation on how SQL memory works in that case will be really appreciate!