Memory usage in Linux R [closed]

Question

I am loading a 6 GB dataset in R running over Centos Linux 6.3, 128 GB RAM, 16 Core machine. Simultaneously I am monitoring the RAM usage with top command. After about 104 minutes, in the output of the top command, the VIRT column shows 189 GB.

Now, I am not able to understand how the VIRT column shows more than 128GB (which is the limit). Is there some kind of shared memory that is being used?

Answer 1

There is simple rule with the virtual memory.

Linux is using RAM for often used processes, but other one it can store at the hard drive, as a virtual memory.

In my opinion, better way to get real memory usage is to use free -m command.