Bug 38118

Summary: New FAQ entry for amount of free memory
Product: Documentation Reporter: Norbert Papke <npapke>
Component: Books & ArticlesAssignee: Murray Stokely <murray>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: Latest   
Hardware: Any   
OS: Any   

Description Norbert Papke 2002-05-15 19:30:01 UTC 
In a recent discussion on comp.unix.bsd.freebsd.misc John S. Dyson
<dyson@iquest.net> provided the following excellent description of free
memory caclulation.  It should be added to the FAQ, possibly in 
"Chapter 16 - Misc Questions".  I have checked with John and he does
not object to his answers being used in this manner.

Q: How much free memory is available?

A: There are a couple of kinds of 'free memory'.
One kind is the amount of memory immediately available without
paging anything else out.   That is approx the size of cache queue
+ size of free queue (with a derating factor, depending upon system
tuning.)   Another kind of 'free memory ' is the total amount of
VM space.   That can be complex, but is dependent upon the amount
of swap space and memory.   Other kinds of 'free memory' descriptions
are also possible, but it is relatively useless to define these,
but rather it i s important to make sure that the paging rate is
kept low, and to avoid running out of swap space.

How-To-Repeat: n/a
Comment 1 Ceri Davies freebsd_committer freebsd_triage 2002-10-28 19:11:52 UTC 
Responsible Changed
From-To: freebsd-doc->ceri

This has been overlooked for too long. 
Remind myself to do this.
Comment 2 Ceri Davies freebsd_committer freebsd_triage 2002-10-28 19:11:52 UTC 
Responsible Changed
From-To: freebsd-doc->ceri

I'll take care of this - remind myself.
Comment 3 Ceri Davies freebsd_committer freebsd_triage 2003-01-23 23:38:45 UTC 
Responsible Changed
From-To: ceri->freebsd-doc

Back to the doc team.
Comment 4 Murray Stokely freebsd_committer freebsd_triage 2003-05-04 23:29:49 UTC 
Responsible Changed
From-To: freebsd-doc->murray

I will look at this one.
Comment 5 Murray Stokely freebsd_committer freebsd_triage 2003-05-05 05:18:25 UTC 
State Changed
From-To: open->closed

I've committed this also to the FAQ.  I added both of these Q&As to 
the system administration chapter, as it seemed slightly more 
appropriate to me than the misc questions, though the FAQ has alwasy 
been rather disorganized. 

Thanks for the excellent submissions!