Along with several insightful answers, I received mail requesting
clarification to the original question. I will be sure to detail
things more clearly in the future!
Many thanks to sun-managers and everyone that responded. I edited out
some of the responses for this summary, but all are appreciated!
The best summary is to say that the optimium solution depends upon the
requirements of a particular site. My question originally assumed
PC's with a local fixed disk for swap and windows config files running
Windows with an NFS connection to a SUN server. The SUN would serve
Windows and Window Applications for the PC's. I wanted first hand
reports of installations supporting this type of environment. Some of
the replies indicated that this was a realistic goal, and described
'typical' configurations that would reasonably support.
The solutions included running IPX on a SPARC as well as SUN
configurations to support NFS connections. Running IPX requires less
memory on the clients and would require less overhead than NFS on the
server, but is expensive to install on the server. NFS is more
expensive to install on the clients, requires more memory and is more
overhead on the server.
IPX Products for SUN Server:
NetWare Sunlink
Connection Netware for SPARC from Prime
SUN hardware products to improve performance:
eNFS NFS acceleration software
PrestoServe NFS write board
SBus Prestoserve board
multiple ethernet segments to improve network throughput
multiple SCSI adaptors for disks to improve disk throughput
Associated information:
"Managing NFS and NIS" by Hal Stern (O'Reilly Associates)
Hal Stern LISA VI 10/92 conference notes on network loading and nfs performance
Response summary below:
8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----
(a little plug for home grown software here) I suggest you consider
"Connection Netware for SPARC", Prime's implementation of Novell for
SPARC.
It turns your SPARC into a non-dedicated Novell file server, and at least
in Australia, for large numbers of PC's (and I reckon 50 - 100 is a large
number) is less expensive than PC/NFS. Also, we have found it to be
marginally faster, and the PC executable code takes less RAM.
Also, should you decide to go to Intel some time down the track, you can
just install a Novell file server, with no need to change any PC
applications or the disk structure. In fact, both the native file server
and SPARC acting as file server can happily co-exist on the same network.
If you like I can send a Postscript summary document for perusal. As a
note, Prime is now called ComputerVision in most parts of the world -- not
sure about Ireland (but this is a recent change, so the phone book will
probably have both still).
Michael Panosh mwp.michael@melpn1.prime.com
Prime, Australia
--------------------------
We've only just started hooking the PC's to the Sun, so we have 5
at the moment, with an additional 20 coming online soon. I've been
doing some reading recently on server capacity and the best
approach to planning seems to start by figuring how many NFS ops/sec/PC
and working up from there to the number of net interfaces needed,
then the number of disks and controllers and finally what kind of
server will handle such a disk/net requirement. A Sparc 2 is supposed
to be able to handle 400 ops/sec on a Lance interface (i.e., le0).
NFS reads are very fast (~900kbyes/sec) but can become a cpu drain,
NFS writes are the hangup (typ ~300kb/sec). For a Sun environment
there are several alternatives to ease these burdens:
NCS co-processor to offload ether/NFS stack operations from the cpu
eNFS NFS acceleration software and the PrestoServe NFS write board
that caches NFS writes into non- volatile memory and immediately
returns a completion to the NFS write request rather than waiting
for the actual disk write to complete and careful disk partition
layout and utilization. Hal Stern of Sun is _the_ authority on
NFS, I would highly recommend looking up his O'Reilly and Associates
book "Managing NFS and NIS" and check through back issues of Usenix
journals to catch any of his articles.
Hal presented a talk on network loading and nfs performance at the
LISA VI, 10/92 conference. I don't know if those papers have been
published yet, but you should check.
Good luck,
Jeff
jeff@millie.loc.gov
--------------------------
What LAN OS ? Novell or PCNFS ?
We have 70 people and 120 PC's running off 2 Sun 3's. (We run Suns off 4/370's,
etc.). The PC's use PCNFS.
We don't do a lot of Windows off the servers, but I don't see that that
particularly matters. We do start a lot of executables off the
servers.
So a SPARC 2 is probably adequate. You can add NFS server cards
(PrestoServe, etc.) if you need a performance boost due to NFS
traffic.
Disk space: allow 200-300 Mb for programs, then # users x space_per for
home directories (which we mount as F:).
Dr. Peter J. Welcher EMAIL: pjw@sma.usna.navy.MIL
--------------------------
A lot depends on how hard you plan on hitting the server. If every user
is using it all the time you will need more than if it's used once in a
while. E.g. If they are all running windows from the NFS disk vs. just
a few, rarely used, applications being on the NFS disk.
We have the latter and 30 PC's is no big deal on a 12MB Sun SLC.
Worstcase is classroom use ("OK students, everyone start SAS"
[shudder]) where you lose the nice way normal use is spread out over
time. I have no idea what is necessary there.
PC-NFS is not particuarly quick by the way. It is my understanding that
Novell is faster (and it's available on a Sun host).
-dave fetrow- INTERNET: fetrow@biostat.washington.edu
--------------------------
I've actually done what you are looking to do, if I read your message
correctly; that is, I supported a network of roughly 100 PCs (at The
Independent, in London) for several years (but not without the rather
skilled help of my colleagues). The clients were running PC-NFS v3,
and the Sun servers were 3/50 and 3/60 workstations with lots of disk.
the ratio of clients to servers was about 25 to 1.
I would feel quite comfortable raising that ratio using SPARC (
and especially SuperSPARC) servers, by perhaps four-fold.
Issues to consider, though, include, but are not limited to:
- Appropriateness of NFS if the environment is all PC clients
(i.e., you might consider the NetWare Sunlink poroduct instead)
- Appropriateness of NFS for performance reasons
(i.e., NFS performance sucks in the absence of accelerators like
prestoServe)
- Need for disk redundancy
(i.e., if I were doing it now, I'd get a license for Sun's Disk Suite
product, and double my disk drives and run disk mirroring).
Dwight A. Ernest dwight@hyphen.com
--------------------------
I will make a proposal based on the limited knowledge about your
applications that I got from your e-mail.
If the maximum node count is around 100, and you want to use a sun as a
server, you could get away with a Sparcstation 2, or a Sparc 10 Model
20 or 30. You could use NFS or IPX/Novell for your file service. I'll
assume NFS since that where most of my knowledge is.
Configure the server with an SBus Prestoserve board. These are a big
win, and you should just go ahead and install it. Then, split your PC's
up on two, maybe three networks. For each network you add (based on
traffic) use an SBUS SCSI/Ethernet card to provide a separate ethernet
segment and an additional SCSI bus. Distribute the disks across the
SCSI buses for best performance. If you have fast and busy PC's, then
try putting about 25/network, perhaps more depending on your experience
with your application. Note that 2 SBUS SCSI/Ethernet boards and one
Presto will fill up the SBUS on an SS2. That would give you a total of
3 ethernets and 3 SCSI (ss2 has built in SCSI and ethernet also).
Then, as that server maxes out, you have to grow from there. I'm
guessing that with PC's as clients the real issue will be disk space,
not network bandwidth.
The harder question in my mind is selecting the PC side client
software. PC/NFS (Sun), PC/TCP (FTP Software), Chameleon (NetManage),
and others are packages that can do NFS client, telnet, ftp, etc.
Choosing one of these involves a lot of tradeoffs. The Chameleon
software looks nice as long as you are in a pure windows environment.
If you need network access from the DOS box, then you will need PC/NFS
or perhaps PC/TCP. SuperTCP from Frontier Technologies can run DOS,
Windows or both at the same time. Some packages also offer mail
readers, news readers, NFS server, etc. Many questions exist in this
area. We went with PC/TCP. This is not the flashiest, but it does seem
to be solid, and is supposed to be a good performer. It also happens to
work with the X windows display server that we use (Hummingbird
Exceed/W). If you want to run X as well, then the choice of IP
networking software for the PC gets even more complex, as the X server
software may only work with some of the IP software. (In our case, I
wanted to try using Frontier Technologies SuperTCP with their PPP
option, but Hummingbird doesn't support that network package. Watch for
similar gotchas.)
If you go with Novell file services, then the above equation is much
simplified since there is only one vendor of the client side software:
Novell.
-Scott Muir
Western Digital Corporation
--------------------------
We have a Sparcserver 2 with 16MB of memory and a dual 669MB SCSI disk
and 2 ethernet cards (vt420 for a terminal). The machine serves a
network split over two physical wires, with about 40 PC's running
PC-NFS and Windows etc..
Performance is good according to the users. We have probably been a
little skimpy with the memory, but apart from that I wouldn't change
anything else.
Richard Bogusz
--------------------------
-- Paul Begley E-Mail: peb@sandoz.ueci.com United Engineers & Constructors Voice: 011-353-21-378811 Ringaskiddy, Ireland FAX: 011-353-21-378285
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