How do I determine how much of physical memory is NOT being used on an AIX machine? Yes, a "bootinfo -r" tells me how much is physically available. And an "ipcs -a" shows me how much of shared memory is being used by the databases on it. I suppose I can add up values from v$sesstat to determine PGA areas (for dedicated server) as well. All that is a given.

But how do I tell how much is not being used at the moment? I know that a "vmstat 1" doesn't tell you that either. The FRE column is not indicative of free memory.