Virtuelni WIN serveri i njihova memorija – objašnjenje

Deo izlaza iz WIN komande “msinfo32” :
Installed Physical Memory (RAM) Not Available
U pitanju je virtielna mašina, pa nema instalirani HW RAM

Total Physical Memory 10.0 GB

Available Physical Memory 449 MB
Ovo je količina SLOBODNE memorije koja je TRENUTNO na raspolaganju.

Total Virtual Memory 19.9 GB

Available Virtual Memory 6.25 GB

Page File Space 9.86 GB
Page File C:\pagefile.sys
Ovo je obično page file za sve WIN servere.
RAM is a limited resource, and, virtual memory is (mostly) unlimited. When the memory being used by all the existing processes exceeds the available RAM, the operating system moves pages of one or more virtual address spaces to the computer’s hard disk. This frees that RAM frame for other uses. In Windows systems, these “paged out” pages are stored in one or more files (pagefile.sys files) in the root of a partition. There can be one such file in each disk partition.
For pagefile the typical recommendation of 1.5 times the installed RAM is a good starting point. On server systems, you typically want to have sufficient RAM so that there is never a shortage and so that the pagefile is basically not used.

In modern OSs such as Windows, applications and many system processes always reference memory by using virtual memory addresses. Virtual memory addresses are automatically translated to real (RAM) addresses by the hardware. Only core parts of the operating system kernel bypass this address translation and use real memory addresses directly.

Virtual memory is always being used, even when the memory that is required by all running processes does not exceed the volume of RAM that is installed on the system.