Free memory in Solaris

I am trying to find out how much physical memory is left after I size my SGA in Solaris. This should be a very basic and simple question. But it almost turns into a nightmare.

I know the answer is NOT vmstat - if thats what you are thinking. It is NOT that simple with Solaris. It IS that simple with HP-UX, that vmstat shows free lists of memory. You can multiple your free lists by 4K and get the free memory in bytes.

I have checked various webs, even with Sun support. There simply has no straight answers. Basically you need 3rd party tools. ( I have no idea what vmstat tells you then, to be honest ). I know man page with vmstat is either wrong or misleading. I says the column free tells you free mem in bytes, then a book I read says it tells you free mem in pages - but neither one matches reality. They are both way off.

Then I read a white paper on Sun Support, it says, it is not easy....etc, and it never gives you a clear answer. I can hardly believe this.

So, there must be trillions of DBAs out there sizing memories in Solaris everyday. How do you guys detemine how much free ( physical ) memory is left on a system? Don't you size stuff like sort_area_size AFTER knowing how much you have free ?

I hope I am completely wrong, because this question seems to be too simple and easy to be answerless. So I am seeking help from the largest pool of Oracle expertises out there - please share your experience if you know how. I would certainly appreciate your help.

-Bass Chorng
 DBA
 Lucent Technologies. Received on Mon Jun 21 1999 - 12:25:15 CDT