SUMMARY: Slow Network performance with ArcView and Samba

[Landert =?UNKNOWN-8BIT?Q?Ren=7Fe ?=]

Thanks for answers, who helped to solve the problem, especially to:
 Paul Ostro [paulo at medphys.ucl.ac.uk]
 steggall at empm.cdpr.ca.gov
 Charlie Brady [cbrady at ind.tansu.com.au]
 Ken Wong [kkwong at ssbux1.env.gov.bc.ca]


To speed up the file transfer from the samba server to the ArcView client application, I had do set the following parameters in smb.conf:
 read prediction = yes
 op_locks = true
 fake oplocks = yes
 socket options = TCP_NODELAY
especially the last option is VERY important!!! The samba server is now 10 times faster then earlier!


The original request is following:

We are experiencing a very slow network when loading files from the Samba server (Samba V1.9.18p4 on Digital Unix V4.0B). A file transfer of a 5 MB file from the samba server to a NT Workstation with FTP takes about 10 seconds. The transfer of the same file with using the NT-Explorer takes also about 10 seconds. The load of the same file (it is a tiff file) with a application called "Imaging" takes 10 seconds too. The load of this file with the application "ArcView" (from the company ESRI) takes about 100 
seconds.

Since the endusers only use the ArcView application, they are very annoyed with the slow performance of the samba server. If we put the file on a NT Server the load times are in every case only 10 seconds.

I have tried to set different parameters in the smb.conf file (read prediction, read size, read raw, locking, oplocks, strict locking, share modes), but nothing gave a little bit of success!

It seems that the application ArcView reads small packets of the data file (between 4KB and 8KB with SMBreadX ), and this slows down the whole process of reading the 5MB file. The application NT-Explorer reads large data packets of 64KB with SMBreadX.

Can anyone give an advise for setting which parameter or compile option?


Rene Landert
Bundesamt fuer Kommunikation
Informatik & Organisation
Zukunftstrasse 44
CH - 2503 Biel/Bienne
E-Mail: rene.landert at bakom.admin.ch
FAX: +41 32 327 55 55
Telefon: +41 32 327 58 98