Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm trying to figure out the meanings of all the different classifications of memory such as VIRT, RES, SHR, AND DATA. While I generally understand the first 3, I have no idea what the DATA column means other than it's official definition as DATA = Data+Stack size (kb). How does this relate to the other 3 classifications of memory?

share|improve this question

From the man pages:

 s: DATA  --  Data+Stack size (kb)
 The amount of physical memory devoted to other than executable code, also known  as
 the ’data resident set’ size or DRS.

In other words memory used to store variable data of for your programs (not executable programs)

Say like and Array in memory is variable data.

Also stack size is like the words say, the size of your stack that the system is using to execute the particular program. The stack is where the system stores the traceback of functions that your program/process is calling. Keep in mind that this metric says the stack size and not the stack itself.

More on the other memory columns that you mentioned here

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.