SUMMARY: Performance tuning advice sought ...

From: Thomas Leitner (tom@finwds01.tu-graz.ac.at)
Date: Fri Aug 14 1998 - 00:57:50 CDT


Hi,

I got several replies and the consensus seems to be, to better
diagnose the desease before trying any cures. So I will talk the
responsible sysadmins into better measuring the bottleneck and
possibly make some tests by temporarily upgrading one of the
Sparc 4's and running it as an X-Terminal before actually
purchasing something. Also cache_fs was mentioned as a solution for
speeding up NFS access. We'll look into this as well.

Thanks to: Tony Lawson <tony@essex.ac.uk>
           Scott F. Woods <sfw@adc.idt.com>
           Matt Reynolds <reynolmd@aston.ac.uk>
           Bismark Espinoza <bismark@alta.jpl.nasa.gov>
           Kevin Sheehan <Kevin.Sheehan@uniq.com.au>
           Steve Phelps <phelpss@ozemail.com.au>
           "Shannon, Patrick" <Patrick.Shannon@Schwab.COM>

(I hope that I did'nt forget anyone).

I'm appending their replies below, followed by my original posting.

Thanks again everybody // Tom

-----------------------------------------------------------------------
From: Tony Lawson <tony@essex.ac.uk>

Presumably price is a consideration, otherwise you could just go and buy
new more powerful machines.
My advice would be to put more memory in one of the sparc-4 systems, up
to say 128MB, which ought to be sufficient memory for single user use of
software like Altera. If this gives you acceptable performance, then you
have the solution, and if not, then you could explore the xterm solution
on one of the Ultra systems.
Unfortunately of course, it may be that neither approach will give
sufficient performance, in which case it is important to spend the
minimum amount in finding this out.

-----------------------------------------------------------------------
From: Scott F. Woods <sfw@adc.idt.com>

We are a vlsi design house so we run similar software to what you
have described. We have found that 64 meg of RAM is way too low
for a workstation running these types of tools and now we have
128 meg minimum in all workstations.

Your problem sounds like it is probably due to slow SPARC 4's though.
On startup most applications don't require too much memory (it's not
until you load a large design). We don't have any SPARC 4's, but
we have many Ultra-1's and I would think that an Ultra-1 with at
least 512 meg of RAM would be able to support > 3 users (for small
designs) much faster than a SPARC 4 with only one user.

-----------------------------------------------------------------------
From: Matt Reynolds <reynolmd@aston.ac.uk>

  I think you may be expecting too much of your Sparc 4's. There's no
way it's ever going to come anywhere near the Ultra's in terms of
performance.

  I don't think b) will achieve anything. I suspect this will actually
slow things down more - as you say, the machines are not swapping too
much, so the problem is more likely to be either CPU power or network
speed. Putting extra load on the network won't help! :-)

  a) may be advantageous. I'd check how much memory the Applications
actually NEED, and then make a judgement. ("top" is a good tool for
debugging memory shortages.) This still won't help though if you're
cpu or network bound though - the previous will only be fixed by
upgrading the 4's either to a faster HyperSparc or an Ultra 5 or
something like that, and the network sounds like there's not a great
deal more you can do with that...

  Are you sure the network is all running at 100 M/s ? Check the boot
up messages for the ultra server to make sure.

     Matt.

-----------------------------------------------------------------------
From: Bismark Espinoza <bismark@alta.jpl.nasa.gov>

If you say only on startup, you may have a network transfer
or IO transfer.

-----------------------------------------------------------------------
From: "Shannon, Patrick" <Patrick.Shannon@Schwab.COM>

I'm not sure of the OS release, but assuming 2.x I'd set sar to collect
data every 20 seconds while attempting to start the application. Then
see where the bottleneck lies using that performance snapshot.

Patrick

-----------------------------------------------------------------------
From: Kevin Sheehan {Consulting Poster Child} <Kevin.Sheehan@uniq.com.au>

Well, before I started applying cures, I'd want to know more about the
disease...

In particular, *why* is startup so slow? Is it a transient paging
problem? Is it something network bound on those that is not on the
Ultra, like NFS?

My *guess* would be that you have the binaries or something on the
Ultra that the SS4s have to get via NFS...

                l & h,
                kev

-----------------------------------------------------------------------
From: Steve Phelps <phelpss@ozemail.com.au>

If you're NFS mounting your application directories and so on, and these
involve large files, you might be able to decrease startup time by using
cachefs with local disks. See "man mount_cachefs". The SS4s probably
don't have enough grunt to drive the 100Meg ethernet at its full throughput;
this might mean that network is the bottleneck in loading the apps accross
NFS (if you are, in fact, mounting the apps via NFS). Caching NFS data on
local disks using cachefs might alleviate this problem.

64MB is not a lot of RAM for Sol 2 box running applications. To see if
you've got a RAM shortage on any box look at the 'sr' column in the output
of "vmstat 5 1000". If it is consistently non-zero then the relavent box
could probably benefit from more RAM.

See Adrian Cockcroft's book "Sun Performance and Tuning" for a comprehensive
intro to tuning sun boxes. Also check out his columns in backissues of Sun
World Online at http://www.sun.com/sunworldonline/, and the se performance
toolkit.

-----------------------------------------------------------------------
From: "Shannon, Patrick" <Patrick.Shannon@Schwab.COM>
To: 'Thomas Leitner' <tom@finwds01.tu-graz.ac.at>
Subject: RE: Performance tuning advice sought ...

In case you're not familiar with it, use the sar script /usr/lib/sa/sa1
as root. I have it run via cron all the time, but only every 10
minutes. The data files can get big...

Patrick

-----------------------------------------------------------------------
From: Steve Phelps <phelpss@ozemail.com.au>

If you're NFS mounting your application directories and so on, and these
involve large files, you might be able to decrease startup time by using
cachefs with local disks. See "man mount_cachefs". The SS4s probably
don't have enough grunt to drive the 100Meg ethernet at its full throughput;
this might mean that network is the bottleneck in loading the apps accross
NFS (if you are, in fact, mounting the apps via NFS). Caching NFS data on
local disks using cachefs might alleviate this problem.

64MB is not a lot of RAM for Sol 2 box running applications. To see if
you've got a RAM shortage on any box look at the 'sr' column in the output
of "vmstat 5 1000". If it is consistently non-zero then the relavent box
could probably benefit from more RAM.

See Adrian Cockcroft's book "Sun Performance and Tuning" for a comprehensive
intro to tuning sun boxes. Also check out his columns in backissues of Sun
World Online at http://www.sun.com/sunworldonline/, and the se performance
toolkit.

------------------- o r i g i n a l p o s t i n g -------------------
From: Thomas Leitner <tom@finwds01.tu-graz.ac.at>
To: Sun Managers List <sun-managers@sunmanagers.ececs.uc.edu>
Subject: Performance tuning advice sought ...

Hi,

I have a question: We have a classroom containing:

            2 Ultra 1/Creator, 167MHz, 256MB RAM
            4 SparcStation 4, 64MB RAM
            1 Sun RAID System connected to one Ultra 1 via
              Fibre Channel
            100 MBit Switched Ethernet between all boxes.
            The first Ultra 1 is the NFS and NIS master server

The students should be able to run CAE tools (Synopsys, COSSAP, Altera
MAXPLUS II) on these machines.

The problem is: On the SparcStation 4, startup of the applications take
awfully long, even though they do not swap too much.

So my question: To tune the performance of the 4 SparcStations, would
we be better off to:

a.) put in more RAM in the SparcStation 4 boxes or
b.) put in more RAM into the 2 Ultras and configure the SparcStation 4
    machines to be dumb X-Terminals, so that each Ultra would be loaded
    with >= 3 users (the local user + 2 * SparcStation 4 users +
    users on other X Terminals eventually).

If b.) would be the way to go: How much RAM should be put into the Ultra 1
machines? 512 MB or more?

Thanks for any hints // Tom

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