Does it make sense to use VSZ from the ps command to monitor memory of processes on a Redhat server?

Solution 1:

It doesn't make any sense to use VSZ for much of anything at all.

This number is the entire amount of virtual memory allocated by the application. This includes memory requested but not actually in use by the application, memory swapped out to disk, pages of the application text itself which haven't even been loaded from disk yet and might never be, and probably a few other things I'm forgetting. Most of this doesn't actually use RAM in the sense you're concerned with.

RSS is actually what you need to be concerned about; that is exactly how much RAM the process is using at any given time.