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:Bruce Weiner-- Setting the Record Straight: Where Linux Today Got It Right and Wrong
Bruce Weiner-- Setting the Record Straight: Where Linux Today Got It Right and Wrong May 4, 1999, 23 :52 UTC (81 Talkback[s]) (8283 reads) (Other stories by Bruce Weiner) |
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By Bruce Weiner
May 4, 1999
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In an April 27, 1999 article entitled "Will Mindcraft II Be Better?"
Linux Today presented a one-sided report clearly designed to destroy
Mindcraft's credibility and to falsely
make our reports look wrong. I want to set the
record straight with this rebuttal, so I'll point out what's right and wrong with
the Linux Today article. Unfortunately, it takes more words to right a wrong than it
does to make someone look wrong, so please bear with me.
What's Right
Dave
Whitinger and Dwight
Johnson had several points right in their
article: |
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Mindcraft did the tests stated in the article
under contract with Microsoft in a Microsoft lab.
Many have tried to imply that
something is wrong with Mindcraft's tests because they were done in a
Microsoft lab. You should know that Mindcraft verified the clients
were set up as we documented in our report and that Mindcraft, not
Microsoft, loaded the server software and tuned it as documented in our
report. In essence, we took over the lab we were
using and verified it was set up fairly.
Mindcraft did conduct
a second test with support from Linus Torvalds, Alan Cox, Jeremy
Allison, Dean Gaudet, and David Miller. Andrew Tridgell provided only one piece
of input before he left on vacation. Mindcraft received excellent support
from these leading members of the Linux community. I thank them for
their help and very much appreciate it.
Jeremy Allison was correct that the I made the
initial contact at the suggestion of a journalist, Lee Gomes from the
Wall Street Journal.
Jeremy was right that we were under an NDA and, as stated above, the tests were
run at a Microsoft lab.
What was not mentioned in the article was the excellent support Red Hat
provided for our second test. Doug Ledford, from Red Hat, answered my
questions on the phone, always called back when I left messages, and
participated in the email correspondence with the above named Linux
experts.
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What's Wrong
Unfortunately,
Mr. Whitinger and Mr. Johnson by not even attempting to contact Mindcraft to get information from
us. It seems as though they wanted to write a one-sided story
from the beginning. The following points will give you the other
side of their story.
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Linus is attributed as saying ".... that nobody in the Linux
community is really working on the Mindcraft test per se, because
Mindcraft hasn't allowed them access to the test site." It's clear from
the emails we exchanged that the Linux experts did make suggestions on
tunes for Linux, Apache, and Samba. They also provided a kernel patch
that was not readily available. We applied all tunes they suggested and the
kernel patch. Here are some of the things that happened:
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Red Hat provided version 1.0 of the MegaRAID driver during our tests and used it, even
though it meant retesting.
We
sent out our Apache and Samba configuration files for review and
received approval of them before we tested. (We actually got better
performance in Apache when we made some changes to the approved
configuration file on our own).
Whenever we got poor performance we sent a
description of out how the system was set up and the performance
numbers we were measuring. The Linux experts and Red Hat told us what
to check out, offered tuning changes, and provided patches to try. We
had several rounds of messages between us in which Mindcraft answered
the questions they posed.
According to the article, Linus complained about
the opaqueness of our test. This is a strange complaint since he and all
of the Linux experts knew the exact configuration of the system
we were testing and knew the benchmarks we were running.
The NetBench and WebBench benchmarks are readily available on the Web
for free and are probably some of the best documented benchmarks
available. We withheld no technical details from him or the other Linux experts.
Jeremy Allison directly contradicts Linus later in the article when he
says "...I can confirm that we have reproduced Mindcraft's NT server numbers here in our
lab." Clearly, Jeremy was tracking what we were doing and had the lab to verify
our results.
The article says that all emails
to the Linux experts came from a Microsoft address. That's wrong. On April
16, 17, 18, and 19 I sent emails to them from Mindcraft's office on
a Mindcraft IP address. Emails sent
during the second test were sent from a Microsoft IP
number.
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Mr. Whitinger and Mr. Johnson are wrong about the email alias of
"will" belonging to me. It belongs to a person who is not a Mindcraft
employee. He is someone who did a posting to a newsgroup about Linux on
the system we were going to use for testing. He wanted to remain as
anonymous as possible because he didn't want to get a ton of flamming
email (based on the email Mindcraft has received, his expectation was
underestimated). I see no need to reveal who he is now because his worst
nightmare will come true and because he had nothing to do with our
test.
Jeremy did give me excellent support both on the
phone and via email. I applied all of his suggestions. If he gave me all
of the
tuning parameters he used for the February 1,
1999 PC Week article
showing Samba performance on a VA Research system, they should have been
applicable to the system I was using. That certainly is true for systems
as similar as those two when running Windows NT Server.
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The Crux of The Matter
The whole controversy over Mindcraft's benchmark
report is about three things: we showed that Windows NT Server was faster
than Linux on an enterprise-class server, Apache did not outperform IIS,
and we didn't get the same performance measurements for Samba that Jeremy
got in the PC Week article or his lab. Let's look at these
issues.
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| Comparing the performance of a
resource-constrained desktop PC with an enterprise-class server is
like saying a go-kart beat a grand prix race car on a go-kart race
course. |
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Smart Reseller reported a head-to-head test of Linux and Windows
NT Server in a January
25, 1999 article; they tested performance on a resource-constrained
266 MHz desktop PC. One cannot reasonably extrapolate the
performance of a resource-constrained desktop PC to an unconstrained,
enterprise-class server with four 400 MHz Xeon processors.
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In a February
1, 1999 article, PC Week tested the file server performance
of Linux and Samba on an enterprise-class system. They did not compare
it to Windows NT Server on the same system. Jeremy Allison helped with
these tests comparing the Linux 2.2 kernel with the Linux 2.0 kernel.
I'll show you below
what he thinks about Windows NT Server on an enterprise-class
server. |
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If you doubt our published Apache performance,
Dean Gaudet, who wrote the
Apache Performance Notes
and
who supported our testing, gives some insights in a recent
newsgroup posting.
In response to a request for tuning Apache for Web benchmarks, Dean
wrote, " Unless by tuning you mean 'replace apache with
something that's actually
fast' ;)
"Really, with the current
multiprocess apache I've never really been able to see more than a
handful of percentage improvement from all the tweaks. It really is a
case of needing a different server architecture to reach the loads
folks want to see in benchmarks."
In other words, Apache cannot achieve the
performance that companies want to see in benchmarks. That's probably
why none of the Unix benchmarks results reported at SPEC
use Apache.
Jeremy Allison believes, according to the Linux Today article, that if we do another benchmark with his help,
"...this doesn't mean Linux will neccessarily [sic] win, (it doesn't when serving Win95
clients here in my lab, although it does when serving NT clients)..." In other words, in a fair test we should
find Windows NT Server outperforming Linux and Samba on the same system.
That's what we found.
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Jeremy's statement in the Linux Today article that "It is a shame that they
[Mindcraft] cannot reproduce the PC Week Linux numbers ..." shows a lack of
understanding of the NetBench benchmark. If he looked at the NetBench documentation
, he would find a very significant reason why
Mindcraft's measured Samba performance was lower:
We used 133 MHz Pentium clients while Jeremy
and PC Week used faster clients, although we don't know how
much faster because neither documented that. We believe that PC
Week uses clients running
with at least a 266 MHz Pentium II CPU. Because
they use clients that are at least twice as fast and because so much of the NetBench
measurements are affected by the clients, this can account for most of the difference in the
reported measurements.
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"You can only compare results if you used the same testbed each time you ran
that test suite."
Understanding and Using NetBench 5.01
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In addition, the following testbed and server differences
add to the measured performance variances:
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Mindcraft used a server with 400 MHz Xeon
processors while PC Week used one with 450 MHz Xeon processors. Jeremy
did not disclose what speed processor he was using.
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Mindcraft used a server with a MegaRAID controller with a
beta driver (which was the latest version available at the time
of the test) for our first test while the PC Week
server used an
eXtremeRAID controller with a fully released driver. The MegaRAID
driver was single threaded while the eXtremeRAID driver was
multi-threaded.
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Mindcraft used Windows 9x clients while Jeremy and PC Week
used Windows NT clients. According to Jeremy, he gets faster
performance with Windows NT clients than with Windows 9x clients.
Given these differences in the testbeds and
servers, is it any wonder we got lower performance than Jeremy and
PC Week
did?
If you scale up our numbers to account for their speed advantage, we
get essentially the same results.
The only reason to use Windows NT clients is to give
Linux and Samba an advantage, if you believe Jeremy's claim. In
the real world, there are many more Windows 9x clients connected to file servers than
Windows NT clients. So benchmarks that use Windows NT clients are unrealistic and
should be viewed as benchmark-special configurations.
The fact that Jeremy did not publish the details
of the testbed he used and the tunes he applied to Linux and Samba is a
violation of the NetBench license. If he had published the tunes he
used, we would have tried them. What's the big secret?
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Jeremy states in the article "The essense of
scientific testing is *repeatability* of the experiment..." I concur
with his assertion. But a scientific test would use the same test apparatus set up and would use the same
initial conditions. Jeremy's unscientific test did not use the same testbed
or even one with client computers of the same speed we used. We
reported enough information in our report so that someone could do
a scientific test to determine the accuracy of our findings. Jeremy did not.
Given the warning in the NetBench documentation against comparing results from different
testbeds, it is Jeremy and Linus that are being unscientific in
their thrashing of Mindcraft's results. Mindcraft never compared its NetBench
results to those produced on a different testbed.
Mindcraft has been in business for over 14 years doing various kinds of
testing. For example, from May 1, 1991 through September 30, 1998
Mindcraft was accredited as a POSIX Testing Laboratory by the National
Voluntary Laboratory Program (NVLAP),
part of the National Institute of Standards and Technology (NIST ).
During that time, Mindcraft did more POSIX FIPS certifications than all
other POSIX labs combined. All of those tests were paid for by the client
seeking certification. NIST saw no conflict of interest in our being paid
by the company seeking certification and NIST reviewed and validated each
test result we submitted. We apply the same honesty to our performance
testing that we do for our conformance testing. To do otherwise would be
foolish and would put us out of business quickly.
Some may ask why we decided not to renew our NVLAP accreditation. The
reason is simple, NIST stopped its POSIX FIPS certification program on
December 31, 1997. That program was picked up by the IEEE and on November
7, 1997 the IEEE announced that they recognized Mindcraft as an Accredited
POSIX Testing Laboratory. We still are IEEE accredited and are still
certifying systems for POSIX FIPS conformance.
We've received many emails and there have been many postings in
newsgroups accusing us of lying in our report about Linux and Windows NT
Server because Microsoft paid for the tests. Nothing could be further from
the truth. No Mindcraft client, including Microsoft, has ever asked us to deliver a report that lied or misrepresented the results of a
test. On the contrary, all of our clients ask us to get the best performance for their
product and for their competitor's
products. They want to know where they really stand. If a client ever
asked us to rig a test, to lie about test results, or to misrepresent test
results, we would decline to do the work.
A few of the emails we've received asked us why the company that
sponsored a comparative benchmark always came out on top. The answer is
simple. When that was not the case our client exercised a clause in the
contract that allowed them to refuse us the right to publish the results.
We've had several such cases.
Mindcraft works much like a CPA hired by a company to audit its books. We give an independent, impartial assessment based on our
testing. Like a CPA we're paid by our client. NVLAP approved test
labs that measure everything from asbestos to the accuracy of scales are
paid by their clients. It is a common practice for test labs
to be paid by their clients.
Considering the defamatory misrepresentations and
bias in the Linux Today article written by Mr. Whitinger and
Mr. Johnson, we believe that Linux Today should take the following actions
in fairness to Mindcraft and its readers:
Remove the article from its Web site and put an apology in
its place. If you do not do that, at least provide a link to this
rebuttal at the top of the article so that your readers can get both
sides of the story.
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Disclose who Mr. Whitinger and Mr. Johnson work for. Were they
paid by someone with a vested interest in seeing Linux outperform
Windows NT Server?
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Disclose who owns Linux Today and if it gets advertising revenue from
companies who do not a vested interest in seeing Linux outperform
Windows NT Server.
Provide fair coverage from an unbiased reporter
of Mindcraft's Open Benchmark
of Windows NT Server and Linux. For this benchmark, we have
invited Linus Torvalds, Jeremy Allison, Red Hat, and all of the other Linux
experts we were in contact with to tune Linux, Apache, and Samba and
to witness all tests. We have also invited Microsoft to tune Windows
NT and to witness the tests. Mindcraft will participate
in this benchmark at its own expense.
The NetBench document entitled Understanding
and Using NetBench 5.01
states on page 24, " You
can only compare results if you used the same testbed each time you ran
that test suite [emphasis added]."
Understanding and Using NetBench 5.01
clearly gives another reason why the performance measurements
Mindcraft reported are so different than the ones Jeremy and PC Week
found. Look what's stated on
page 236, "Client-side caching occurs when the client is able to place
some or all of the test workspace into its local RAM, which it then uses
as a file cache. When the client caches these test files, the client can
satisfy locally requests that normally require a network access. Because a
client's RAM can handle a request many times faster than it takes that
same request to traverse the LAN, the client's throughput scores show a
definite rise over scores when no client-side caching occurs. In
fact, the client's throughput numbers with client-side caching can
increase to levels that are two to three times faster than is possible
given the physical speed of the particular network [emphasis added]."
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Copyright © 1999. Mindcraft, Inc. All rights reserved.
Mindcraft is a registered trademark of Mindcraft, Inc. Other product and corporate names
are trademarks and/or registered trademarks of their respective companies.
For more information, contact us
at: info@mindcraft.com
Phone: +1 (408) 364-2860
Fax: +1 (408) 364-2862


| Talkback(s) |
Name and Date |
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Jeremy Allison May 4, 1999, 21:17:17 |
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Ed Centanni May 4, 1999, 21:33:29 |
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Patrick Lambert May 4, 1999, 21:38:36 |
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Eric Lee Green May 4, 1999, 21:50:10 |
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Ken Witherow May 4, 1999, 21:50:29 |
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Ben Tilly May 4, 1999, 21:54:07 |
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gimme choice May 4, 1999, 21:57:56 |
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Navindra Umanee May 4, 1999, 22:02:28 |
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Joshua Kramer May 4, 1999, 22:05:30 |
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Borg May 4, 1999, 22:10:24 |
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King Lee May 4, 1999, 22:12:39 |
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is3 May 4, 1999, 22:21:14 |
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Jon Cromwell May 4, 1999, 22:31:03 |
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liang May 4, 1999, 22:37:00 |
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Larry J. Blunk May 4, 1999, 22:49:25 |
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Marcus Andree May 4, 1999, 22:49:50 |
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Mohammad Bahathir Hashim May 4, 1999, 22:53:39 |
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Jonathan Benson May 4, 1999, 23:05:56 |
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Low, Kuan Loong May 4, 1999, 23:13:09 |
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AC May 4, 1999, 23:13:19 |
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Donald Duck May 4, 1999, 23:15:22 |
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John Dobbins May 4, 1999, 23:26:21 |
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Ramana Juvvadi May 4, 1999, 23:43:28 |
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Prem Kurian Philip May 5, 1999, 00:08:11 |
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Lukas J. Dickie May 5, 1999, 00:35:57 |
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Shane Ng May 5, 1999, 02:14:03 |
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M Cheema May 5, 1999, 02:21:37 |
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Anthony E. Greene May 5, 1999, 03:02:54 |
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Niall Murphy May 5, 1999, 04:34:39 |
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Tim Hanson May 5, 1999, 05:06:26 |
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J Sanford May 5, 1999, 05:22:47 |
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Camelot May 5, 1999, 05:50:40 |
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Tet May 5, 1999, 06:16:11 |
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Vikas Agnihotri May 5, 1999, 06:22:21 |
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Mark Evans May 5, 1999, 06:26:07 |
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thierry May 5, 1999, 07:00:34 |
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Bill Stephens May 5, 1999, 08:03:21 |
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Steve Poling May 5, 1999, 08:23:32 |
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Scott E. Regener May 5, 1999, 08:28:46 |
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Mike Bohlmann May 5, 1999, 08:43:25 |
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Marc Simont May 5, 1999, 08:57:44 |
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Scott Davis May 5, 1999, 09:22:33 |
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Matt Wilbur May 5, 1999, 10:12:16 |
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Mario May 5, 1999, 10:12:59 |
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Rocky Welch May 5, 1999, 10:31:09 |
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HM Johnson May 5, 1999, 10:33:17 |
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Michael J. Ball May 5, 1999, 10:35:54 |
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Joshua Taylor May 5, 1999, 11:05:25 |
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Marcus May 5, 1999, 11:21:20 |
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Jeff Licquia May 5, 1999, 11:38:39 |
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Rocky Welch May 5, 1999, 12:19:18 |
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M Cheema May 5, 1999, 13:24:59 |
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S.Mitchell May 5, 1999, 14:39:24 |
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Ken Beal May 5, 1999, 16:50:00 |
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Daniel Weber May 5, 1999, 16:55:26 |
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totoy May 5, 1999, 22:05:50 |
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Erik Warmelink May 5, 1999, 23:03:20 |
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mirschick May 6, 1999, 11:55:02 |
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Casey McCoy May 6, 1999, 12:27:26 |
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Vox May 7, 1999, 04:51:29 |
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Bjorn Stadil May 8, 1999, 01:16:21 |
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Mark Finch May 9, 1999, 13:22:36 |
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s chung May 15, 1999, 07:31:44 |
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Andy Thomas May 18, 1999, 15:10:33 |
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Brent F May 18, 1999, 20:18:00 |
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Strider Centaur May 20, 1999, 13:17:18 |
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LiNT May 21, 1999, 08:26:41 |
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LiNT May 21, 1999, 09:22:48 |
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matt christian May 22, 1999, 00:52:20 |
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LiNT May 22, 1999, 10:43:53 |
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Izak Burger May 22, 1999, 17:52:11 |
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Stuart Fox May 23, 1999, 18:55:58 |
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Chris Jun 1, 1999, 03:31:27 |
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Chris Jun 1, 1999, 03:57:44 |
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Chris Jun 1, 1999, 04:09:05 |
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Chris Jun 1, 1999, 04:21:39 |
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Chris Jun 25, 1999, 12:16:22 |
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Spartacle Jul 6, 1999, 22:43:39 |
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