Packet analysis: WinXP vs. Linux<->VMS shows dramatic differ ences

[COLLOT Jean-Yves]

Hi.

I was very interested (and very surprised) by the experiments and results
described in the last messages, so I tried to reproduce the issue myself.

Note that, instead of using Ethereal or other utilities, you can run smbd
with log level 3, and all the transactions are logged.

I downloaded the "ruby" stuff, and I ran the bench provided by Ben
Armstrong. I saw exactly the behaviour described by Ben (1024 bytes writes,
1 byte writes, QUERY_FILE_INFOs, etc..). The result is incredibly slow.

I did some other tests with a simple "copy" DOS command, and with copy/paste
clicks in the Windows Explorer. Those times, there was only 61 Kb writes. No
more 1024 bytes writes, no more 1 byte writes, no more QUERY_FILE_INFOs, and
good performances.

I then used a utility (http://www.pc-tools.net/win32/ptime/) that you may
know, and that enables you to get the execution time of a command.

Here are the results, for a "COPY BENCH.TMP Z:\BENCH.TMP" command :

- BENCH.TMP is a 10000 Kb local file (the file created by Ben's ruby bench)
- My whole network is 100Mbits/Full Duplex
- My client is a Windows XP/SP2 PC
- when Z: is a Samba/Linux box (bi-processors Intel 2Ghz), the elapsed time
is 2.75 seconds
- when Z: is a Windows NT server (a quite old one, I don't know exactly the
type), the elapsed time is 3.79 seconds
- when Z: is a Samba/VMS Alpha DS20-666, the elapsed time is 2.35 seconds

As you see, the performances of Samba/VMS are not so bad.

My feeling is that there are some strange things happening between
Windows/Ruby and the Samba/VMS server. Fixing that will probably be quite
difficult, and will probably demand analysis of the Ruby code as much as the
Samba code, in order to understand what happens.

Is this Ruby thing used by many people? Do any of you have similar very bad
performances when writing a file, but with other software?

JYC