Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!kaukau.comp.vuw.ac.nz!andy
From: andy@comp.vuw.ac.nz (Andy Bond)
Newsgroups: comp.sys.hp
Subject: Re: swap space for diskless clients
Keywords: swap
Message-ID: <1990May08.005706.17907@comp.vuw.ac.nz>
Date: 8 May 90 00:57:06 GMT
References: <1990Apr30.024120.20924@comp.vuw.ac.nz> <1080149@hpfcmgw.HP.COM>
Sender: news@comp.vuw.ac.nz (News Admin)
Organization: Distributed Systems Group, Comp Sci, Victoria University of Wellington
Lines: 45

In article <1080149@hpfcmgw.HP.COM> dale@hpfcmgw.HP.COM (Dale McCluskey) writes:
[...]
>I'll echo what others have said: "monitor" is the tool of choice for 
>looking into this stuff - the "K" screen will be particularly helpful 
>in this case.

Since my initial query, I have had several email messages recommending
I use monitor.  I agree that it is very useful, but it addresses a
different problem than that which faces me.  Let me explain ...

I am extending rstatd for use in a multi-vendor network so that it
will return, among other things, statistics of virtual and real memory
usage.  Since rstatd is an RPC based routine, I require it to perform
queries efficiently with as little impact on the local host as
possible.  Since a lot of other information is being gathered from the
kernel at this time, I want to know how to obtain this memory usage
information from the kernel.  On our 835, I can obtain the required
information via:

Used Real Memory = _physmem - _total.t_free
Free Real Memory = _total.t_free

Used Virtual Memory = _nswap - _total.t_vm
Free Virtual Memory = _total.t_vm

(BTW, I know that t_vm isn't exact but at least it's in the ball park)

On our HP300 cluster, the virtual memory values don't get me what I
want to know.  Each node (diskless clients and server), reports
_total.t_vm correctly for the local node, but only the server knows
_nswap (which really doesn't help as it doesn't know the usage of the
diskless nodes).  I want some way of locally (this is important, I
don't want to be remotely getting _total.t_vm for all the nodes)
finding the amount of space left on the swap device that each client
uses (since they're shared, it's probably going to fairly large).

I hope this clears up any confusion.

thanks for any help,
andy
--
Internet: andy@comp.vuw.ac.nz      |    Andy Bond, Dept. of Computer Science
Phone:    (04) 721-000 ext. 8144   |    Victoria University
Fax:      (04) 712-070             |    P.O. Box 600, Wellington, New Zealand
		   Beware the fury of a patient man