Xref: utzoo comp.unix.ultrix:3099 comp.sys.dec:2911
Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!cbmvax!grr
From: grr@cbmvax.commodore.com (George Robbins)
Newsgroups: comp.unix.ultrix,comp.sys.dec
Subject: Re: what are 'missing' pages?
Message-ID: <10426@cbmvax.commodore.com>
Date: 29 Mar 90 10:36:40 GMT
References: <1963@naucse.UUCP>
Reply-To: grr@cbmvax (George Robbins)
Organization: Commodore, West Chester, PA
Lines: 55

In article <1963@naucse.UUCP> sbw@naucse.UUCP (Steve Wampler) writes:
> 
> The world:
> 	uVAX-III with 16MB main memory and two 20MB swap partitions
> 	(not on the internal DEC disks but on two SCSI drives).
> 	Ultrix 2.2 OS.
> 
> We've had trouble lately with malloc()'s failing do to
> 'lack of core' or 'lack of swap space', even though we
> are not approaching the total 56 MB above.  It looks
> as though (I'm not sure because I don't really know how
> to check) this happens when the total virtual memory
> of running processes exceeds the amount of physical
> memory (16MB).
> 
> Is this 'expected' behavior?  We're talking BIG malloc's
> by the way - typically 1 to 3 MB.
> 
> Here's the output of 'pstat -s'
> 
> 	11661k used (1357k text), 8781k free, 3240k wasted, 40781k missing
> 	avail: 13*512k 2*256k 3*128k 7*64k 10*32k 12*16k 269*1k

Let's ignore the numbers and check the bases...

1) do you have the second swap area defined in /etc/fstab as a :sw: partition
	type and have a "swapon -a" comand executed in your /etc/rc?  (or
	explicitly specified as "swapon /dev/xxnb", I forget when this changed)

2) do you really have two swap areas define in the system configuration file
	in the "swap on xxnb and xxnb" statement?

3) does the value for physmem in your config file equal or exceed the amount
	of physical memory installed in the machine?

4) do the values of dmmin and dmmax (or their defaults) support a large enough
	virtual memory limit to utilize all the swap space.

5) is a lot of space being wasted for getttys or other non-important processes
	due to vmmin being too small to fit the processes into the initial
	allocation?

If you check out on 1-4, then I'm out of clever suggestions.  Number 5 is more
of a tuning thing that helped me back when I had lots of often inactive gettys
and not much swap space.

> Anyway, if someone can guide me in the true path to enlightenment, I'd
> be effusively thankful.

Me too...  8-)

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)