Thanks in advance,
Chuck Howell
how...@mitre.arpa
My personal experience with Sun-2's running 2.x or 3.x or Sun-3's running 3.x
on various file server configuration have shown me that they (file servers)
are not memory bound. Our file servers usually don't even have Sun consoles
on them so they never run suntools. That makes a tremendous difference to
file server performance. For the rest, a file server typically runs a much
smaller subset of programs (i.e. nfs stuff, network daemons) than a normal
client (i.e. editors, graphix, databases, AI development). We also discourage
"logging-in" to the file server to minimize character based I/O interrupt
handling. Why not ? Everything is accessible over NFS.
Don't have much experience with 8MB Sun-3/75 as diskless clients. Just got
one, but I recommend throwing memory at clients instead for file servers.
Take a good look at your file server using vmstat and you'll be suprised.
Here's how we configure 'em:
Hardware OS MB # clients Disks
Sun-2/170 2.3 2 ~12-17 451, 2 Eagles (~760 MB)
Sun-3/180 3.0 4 ~10-12 451, 2 Super Eagles (~1.1 GB)
Tim Ehrhart, SRI International, Menlo Park, CA 94025
If the file server is also used as a workstation the same applies.
However, we do not see much performance degradation in a 4 Meg server
over an 8 Meg server, so long as no one logs in. I personally am less
certain of this result, however, since we haven't actually tried to
measure it. The performance improvement in 8 Meg over 4 Meg in a
workstation, however, is immediate and dramatic.
This is, of course, for systems running 3.0. The way Sun
software grows (and grows and grows and...), all bets are off with
the next major release.
[and in a follow-up article, he clams the same is true for a 3/50, since
4 Meg is all you can ever put on that machine]
We've got 12 3/50's here and I havn't seen the memory thrashing
described above. My .suntools sets up 3 perfmeters (local, and keeping an
eye on our 2 file servers), a clocktool (w/ second hand), an rlogin to our
vax, a console, a mailtool, and 3 shelltools (2 iconic). Typically I've
got an emacs running in one window with some sort of big troff or make in
another. With the clock and perfmeters waking up every second or two, that
keeps the machine pretty busy. I don't notice any wild paging going on,
and almost never any swapping.
I suppose it all depends on what kind of jobs you're running. Add
to that mix some horrible lisp thing and a 1k x 1k matrix multiply and I
would imagine you'll see some vm activity pretty fast.
When we started negotiating the purchase of our systems, the 3/50
hadn't been announced yet and we were looking at the 3/75. Since we had
been running as many as a dozen users on our 4 Meg vax without problems, I
couldn't believe you would want 4 Meg in a personal workstation and decided
to save some money by buying the 3/75-2 (i.e. 2 Meg). (To this day, some
part of me is still living in the days when we ran 24 users on a 96k 11/45
with a 20k v6 kernel; now we run 1 Meg 4.2 kernels.)
I was rather annoyed when our salesman tried very hard to talk us
out of it, and surprised (and even more annoyed) when he claimed that they
didn't even make the 3/75-2's in their catalog. Talking further with some
high-level technical people at Sun convinced me they were right. "So, if
you won't sell me a 2 Meg system, why do you have them in your catalog at
all?", I asked. The answer basicly turned out that in order to meet
bidding requirements on certain sales, they needed to be able to present a
system with a lower price tag than the 3/75-4.
It was around that time that I was getting fed up with Sun (I don't
think the Sequent people realize just how close they came to making a sale
then) but the announcement of the 3/50 sold me. Now we have our 4 Meg
systems, and we're happy. And I *still* think 2 Meg would have been
plenty! 1/2 :-)
--
Roy Smith, {allegra,philabs}!phri!roy
System Administrator, Public Health Research Institute
455 First Avenue, New York, NY 10016
minimum_memory_size = 1 << (19+sun_release_number);
Thus, my Sun 3/75 comfortably runs Sun release 3.1 with 4Mb. This
includes Suntools (or X -- I've used both), several simultaneous
shells, rlogins, etc. Our Sun 2's run release 2.0 happily with 2Mb.
My workload is shells, rlogins, editors, compilers, etc. (People here
who run large computations require more memory. Some users are
complaining that 16Mb on a 3/180 isn't enough.)
--
John Bruner (S-1 Project, Lawrence Livermore National Laboratory)
MILNET: jdb@mordor [j...@s1-c.ARPA] (415) 422-0758
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