Confused with virtual memory!

[Manuv16589]

Hi members,
If i am right so virtual memory address space is the one that is assigned to memory locations on hard disk that will be used by ram. Is that address assigned to every data on hard disk or to those only required for execution?

 

[gabeNC]

If i am right so virtual memory address space is the one that is assigned to memory locations on hard disk that will be used by ram.

Close, but not quite. You are thinking of Paging and sometimes people use that term interchangeable. In modern operating systems the virtual memory is a combination of actual physical ram and any paging you may have on the disk. This is tunable, you may not want the computer to use any physical disk (paging) as it is VERY slow. You pay a massive performance hit for reading from the disk. Years ago it was common practice to have 2.5 times the paging as physical memory, because ram was very expensive. The virtual memory manager is responsible for managing context switching between the two different types of memory.