Hi,

I have a query regarding top & virtual memory.
When we run top it show VIRT (Virtual Mem), RES (Resident Mem) & SHR (Shared Memory).
The total virtual memory of my machine is 4 GBs (2 GB RAM + 2 GB Swap),
but still I am able to see a process showing 4000m virtual memory column.

Can you explain what it means, as its show VIRT Mem more than actual available VIRT memory

Thanks in advanced.
Meghanand

That is not the correct meaning of the term "virtual memory".

Swap space is used for just "anonymous" memory. Actual ram is used for many things, including anonymous memory.

The VIRT size of each task includes some anonymous memory and several other categories of memory and several categories of committed but not actually allocated memory.

VIRT for a single process could be more than the sum of ram plus swap for many reasons (though in your example, you seem to be saying VIRT for one process is slightly less than the sum of ram plus swap).

The total VIRT for all processes may be more than the sum of ram plus swap for even more reasons.

The comparison you are trying to make has little meaning.