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A candid talk about increasing performance of a Novell network.
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A candid talk about increasing performance of a Novell network.
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05/19/87


A Discussion of Novell Netware
with tips for this and that.

Henry J. Franzoni III

After installing a number of Novell networks I have
decided to share a few of my discoveries. Some of these
may help improve performance on your network. Some of this
information is available from "Netwire", the Novell BBS on the
Source BBS, and some of it is available in the two publications
published by Novell, "LAN Evaluation Report 1986", and "LAN
Operating System Report 1986", available for the asking.

The last version of Netware that ran on all sorts of
PC compatibles is Netware 86 version 4.61b. After this came
Advanced Netware 86 version 1.02, and then Advanced Netware 286
version 2.0a. The latter two need an IBM AT or very close clone
as the file server since the protected mode of the 80286 chip
is used by Advanced Netware. Advanced Netware 86 version 1.02
is an orphan, avoid if possible. Advanced Netware 286 version 2.0a
is the latest version, and is quite improved over earlier versions.

Performance of a network is mostly dependant on two measures
of speed, the actual processing speed of the terminals, and the
speed of data being transferred on and off the network volumes.
To provide some basis for comparison, the average speed of and
IBM XT 10Mg hard disk transferring data is 44Kb/sec. The average
speed of an IBM AT 20Mg hard disk is 120Kb/sec. Any application
that reads and writes a lot to the disk, such as database or
word processing, will have to pass through this I/O bottleneck.

To measure this transfer rate, Novell provides "Perform.arc"
on their Netwire service. I don't know if "Perform" is in the
public domain or not, but registered Netwire users can get it for
free. Perform allows one to read and write files on the network
volume and gives results in Kb/sec. Different parameters can be
altered. Records can be as small as 128 bytes or as large as
4096 bytes. The number of records read or written can be changed
from 1 to at least 9000. The file can be a sequential file or an
overlayed file. This can be important since reading an overlayed
file will test the speed of the network and not the disk, since
the overlayed file can easily fit in file server RAM.

Novell publishes a series of results in the "LAN Evaluation
1986" that use Perform. The setting used is reading 100
overlayed 4096 byte records. One can compare results with the
chart on page 72 for a single station, or the chart on page 75
for six stations simultaneously. The results on page 75 are obtained
by adding together the results on each of the six terminals.
Briefly, these are some results for a single station:

SERVER TYPE

Network 386 286A PC AT PC XT
Type: 16Mgz 8Mgz 6Mgz 4.77Mgz

Arcnet 70.67 64.41 44.40
3 Com Ethernet 173.16 174.93 144.40 77.52
Gateway G-net 32.52 31.27 25.54
Corvus Omninet 32.23 32.65 26.58
Proteon Pronet 104.85 88.69 57.80
IBM Token Ring 85.65 80.97 60.70
AT&T Starlan 53.55 48.84 37.14

The measurements are in Kb/sec. IBM AT's were used as terminals.
An Etherlink Plus board was used on the file server and regular
Etherlink boards in the terminals for the Etherlink measurement.
This seems to be the best Etherlink configuration. Novell does
not supply the drivers for using an Etherlink plus board in the
terminals, only in the file server.

The 286A is Novell's own file server hardware, the 286B results
are very close to the 286A results.

When a Deskpro 386 was used as a terminal as well as the file server
with an Etherlink hookup, the speed was 208.33Kb/sec.

When an IBM PC was used as the terminal with the Etherlink hookup,
the speed was always 60Kb/sec., regardless of the file server used.
This is about a 70% loss of performance with an AT file server.

When an IBM PC was used as the terminal with the Gateway hookup,
the speed was 25.15Kb/sec., which is a very small performance loss.

Arcnet doesn't degrade much, but with a maximun throughput of
70.67Kb/sec. it isn't as fast as an AT hard disk.

What does this mean? To me it means that one needs to use Etherlink
cards if one would like performance equal or better than an IBM AT
20 mg hard disk. (120Kb/sec.) When six terminals are simultaneously
reading files under Etherlink the performance slows to 68.35Kb/sec.
when using an 8Mgz AT file server. Under Arcnet, the reading
was 19.21Kb/sec. at each terminal. The IBM token ring network with
only four stations dropped to 60.33Kb/sec. per station.

The key difference for me between token passing networks (Arcnet,
IBM Token Ring) and the contention networks (Ethernet, Proteon) is
timing. If your network requires precise timing at each terminal,
such as in some manufacturing control applications, only the token
passing networks offer a way to do this. The contention networks
share file server resources on a first come, first served basis,
so it is possible that one terminal may hog the file server and not
let others use it for a few moments. The token passing networks
share file server resources equally regardless of network load.

The performance can be altered with various software settings.
The number of open files, size of blocks read and written, number
of directory entries, and number of search drives all affect the
overall network speed. Generally, I find that using the maximum
block read/write size, (4096 bytes), and the minimum of everything
else, (directory entries, open files, search drives), maximizes
performance. Since Netware 286 uses the remaining server RAM for
file caching, the following formula may be of help to determine
file server memory usage:

D=No. of directory entries on all volumes (files)
F=No. of file handles (Open simultaneously)
V=No. of Volumes
U=No. of active users
K=one Kilobyte (1024 bytes)
M=Amount of memory left over for file caching

M = 230K + 40D + 100F + 500V + 8KU

Generally, the more memory available for file caching,
the faster the overall network throughput.

Here are some other random tips. Netwire usually has
a few improved drivers for Netware. Lately I downloaded
improved Etherlink drivers. Backup devices have to be
connected to a terminal, not the file server. The drivers
to connect a Bernoulli Box right to the file server are
available for Netware 86 version 4.61b only, Advanced
Netware 286 isn't supported yet according to the guy I spoke with.

When buying cable such as RG 59 U (cable TV cable), remember
that type RG 59 U/B is the military spec. cable of the same type
and has additional shielding. Most vendors haven't heard of the
military version of cable, but it works better if you can find it.
I haven't been able to locate RG 58 U/B yet, just RG 58 U. This
is used in some Ethernet Hookups.

I hope this helps some of you out there.

Henry J. Franzoni III
65 Nassau St. Apt. 10c
New York, NY 10038-4507
(212) 732-5473


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