Conference hydra::axp-developer

From:	DEC:.REO.REOVTX::HUDSON       "[email protected] - UK Software
Partner Engineering 830-4121" 29-JAN-1997 12:17:22.50
To:	nm%vbormc::"[email protected]"
CC:	HUDSON
Subj:	RE:excessive swapping on VMS 32Mb system

Hello Peter,

Thanks for your question on excessive swap-outs.

The short answer to your question is that you need to add extra physical
memory to your machine (solution 1), or reduce the memory requirement of the
processes that you're running (solution 2).

You say you have 32Mb, and the 6.2 SPD for VMS says "The minimum amount of
memory required to install, boot, and log in to an OpenVMS Alpha system is 32
MB.  To ensure satisfactory performance for particular applications or numbers
of users, additional memory may be required."

From the SHOW SYSTEM you are running Motif, TCP/IP and DECnet, and a fair
number of other processes, so I don't think the system is behaving in an
unexpected way when it is swapping out so many processes.

Processes being swapped out is not necessarily a bad thing.  If a process isn't
doing something, then on a memory-constrained system such as yours, you want
that process to be swapped out and left there.  It is a problem if the demand
on memory is such that a set of processes are continually being swapped in and
out.  If that is happening, then this indicates that the collection of
processes you have has a net memory requirement which exceeds the physical
memory available.  The only thing you can do about this is to add memory
(solution 1), or reduce the memory requirement of the processes (solution 2).

If you have, say, 10 processes, which when they're all running need an
aggregate 40Mb of physical memory, then no matter what you do to your system
parameters, VMS is going to have to be moving things to and fro from the disk
in order to keep going.  If it wasn't swapping, it would have to page, or just
lock up altogether.

It is conceivable that by tweaking some of the SYSGEN parameters you may affect
the behaviour of the system a bit, but I this will likely be a bit of a
hit-and-miss affair, and I would be surprised if you can significantly improve
on whatever the settings are that AUTOGEN has derived.

For example, it may be possible that you could cut down on swapping by
constraining the physical memory that processes are allowed (i.e. reducing
working-set extents).  This might have the effect of making processes use less
physical memory, which might mean that you'd get more processes on before
swapping started.  But then the processes would just be paging more, which
could quite easily mean poorer performance than the original swapping was
causing.

Over a period of time, you should find that the processes swapped out are those
which aren't doing much (and so don't need to be swapped in).  For example on
your SHOW SYSTEM, you can see ERRFMT and OPCOM swapped out.  You can stop
processes from being swapped out by using "SET PROCESS/NOSWAP", but if you
apply that to an interactive process that belongs to someone who has gone to
lunch, you're wasting a lot of resources.  And that won't stop them being paged
out to disk.


Looking at your SHOW SYSTEM, the process with the most physical memory by far
is a DECW$TE... session.  This is what you get when you're running a DECterm. 
DECterms use a lot of memory, so maybe you could avoid having them running on
this machine (solution 2).  In fact if you could use this machine as a server
rather than a workstation (i.e. don't run DECwindows), I think that would free
up a fair amount of memory (solution 2).  Incidentally, the DTLOGIN and DTGREET
processes are DECwindows processes.

If you want to run without DECwindows, you can define the logical
"DECW$IGNORE_DECWINDOWS" to "TRUE" inside SYS$STARTUP:SYSTARTUP_VMS.COM.

I hope this is of some help to you.  I'm sorry that there isn't an easier
answer along the lines of "increase this SYSGEN parameter"...

Regards

Nick Hudson
Digital Software Partner Engineering

From:	HYDRA::AXPDEVELOPER "[email protected]" 30-JAN-1997 07:48:21.76
To:	rdgeng::hudson
CC:	AXPDEVELOPER
Subj:	FWD: Re: Xcursions error msg  

From:	SMTP%"[email protected]"   29-JAN-1997 17:27:27.95
To:	Peter Romano <[email protected]>
CC:	[email protected], [email protected]
Subj:	Re: Xcursions error msg  

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Message-Id: <[email protected]>
To: Peter Romano <[email protected]>
Cc: [email protected], [email protected]
Subject: Re: Xcursions error msg  
In-Reply-To: Your message of "Wed, 29 Jan 97 09:26:00 EST."
             <83970129142638/[email protected]> 
Date: Wed, 29 Jan 97 16:59:20 -0500
X-Mts: smtp


Hi Peter,

I will forward your question to our ASAP hotline
support.  One of our on-duty technical support
staff will response to you shortly.  If you
have further technical questions and issues,
please feel free to call us or send email 
to [email protected].

Regards,
Miller


ate: Wed, 29 Jan 97 09:26 EST
From: Peter Romano <[email protected]>
To: chin <[email protected]>
Subject: Xcursions error msg
Message-Id: <83970129142638/[email protected]>

ATTN:
Mr. Miller Chin, DEC ASAP Group

Hello Miller:

I was able to resolve the issue of the DTLOGIN and DTGREET
processes on my Alpha which I noted in my last e-mail by calling
CSC. These processes result by default from fact that Alphastation
is a graphics station (ie: with a graphics device) and so the CDE
environment is started. CSC told me how to avoid these processes
by setting a symbol in my CDESTARTUP.com and also how to avoid
the 2 DECW$server processes to avoid their overhead. That is done
by adding 2 symbol values to SYSTARTUP_VMS.COM.

I now have a question re: following excursions log message which I get
from time to time and thjat I would like to eliminate. Could you
please provide necessary information for resolution.

1/28/97    7:15:03 PM   X server Error  XDM:  too many retransmissions


Thanks,

Peter Romano
Prime Associates Inc.

6359777 at MCIMAIL.com
908-603-0956 voice

end

From:	DEC:.REO.REOVTX::HUDSON       "[email protected] - UK Software
Partner Engineering 830-4121" 30-JAN-1997 16:04:28.75
To:	nm%vbormc::"[email protected]"
CC:	HUDSON
Subj:	RE:  Xcursions error msg  

Hello Peter,

>I now have a question re: following excursions log message which I get
>from time to time and thjat I would like to eliminate. Could you
>please provide necessary information for resolution.
>
>1/28/97    7:15:03 PM   X server Error  XDM:  too many retransmissions


I can't find reference to this error anywhere on any of our internal databases.

Can you tell me

	- what's the exact format of the message (if it isn't what you've
	  written above)
	- where this error appears (on the console? in a file? which file?)
	- how often you're seeing the error
	- what other errors you're seeing around the same time (if any)
	- whether you're noticing anything fail on the system at around the
 	  time these errors occur
	- when you first noticed the errors

Regards

Nick Hudson
Digital Software Partner Engineering

From:	DEC:.REO.REOVTX::HUDSON       "[email protected] - UK Software
Partner Engineering 830-4121" 20-FEB-1997 10:28:11.15
To:	nm%vbormc::"[email protected]"
CC:	HUDSON
Subj:	re: xcursion error message

Hello Peter

A while ago you mailed in a problem description with an error you were getting
from X server relating to excursion.  I sent you the following mail on 30-Jan
but haven't heard from you since.  Is this still causing you a problem or have
you resolved it now?

Regards

Nick Hudson
Digital Software Partner Engineering


> Hello Peter,
> 
> >I now have a question re: following excursions log message which I get
> >from time to time and thjat I would like to eliminate. Could you
> >please provide necessary information for resolution.
> >
> >1/28/97    7:15:03 PM   X server Error  XDM:  too many retransmissions
> 
> 
> I can't find reference to this error anywhere on any of our internal databases.
> 
> Can you tell me
> 
> 	- what's the exact format of the message (if it isn't what you've
> 	  written above)
> 	- where this error appears (on the console? in a file? which file?)
> 	- how often you're seeing the error
> 	- what other errors you're seeing around the same time (if any)
> 	- whether you're noticing anything fail on the system at around the
>  	  time these errors occur
> 	- when you first noticed the errors
> 
> Regards
> 
> Nick Hudson
> Digital Software Partner Engineering
> 

timed out