Samba performance on Fast Ethernet networks when linked to Win95

[Constantin Teodorescu]

Hello everybody,

althought there are a lot of discussions on Samba's performance, I would
like to share my results trying to connect Samba running on a Linux box
to a Win95 workstation on a fast ethernet network.
If any of you could have some ideas or suggestions , please mail me (cc:
teo at flex.ro) because I am not (yet) on this mail list.

First of all, may I present you :

1. THE SERVER - Compaq PROLIANT 800
   Pentium Pro 200 MHz, 64 Mb RAM
   2 Gb SCSI HDD Fujitsu
   Allied Telesyn 10/100 Ethernet card, UTP
   Linux 20.32 + Samba 1.9.17p4

2. THE WORKSTATION
   Pentium 100 MHz, 16 Mb RAM
   1,2 Gb EIDE HDD
   Allied Telesyn 10/100 Ethernet card, UTP
   Windows 95

Those 2 computers where linked through a Fast Ethernet Allied Telesyn
hub, UTP. No other disturbing workstations were conected to the HUB.

I have read Speed.txt many times, I have read *all* the mailing lists
concerning Samba's performance , tried a lot of parameter values
combination on server and workstation but the results still are poor.

THE RESULTS
***********
The tests were made using a 25 Mb file for transferring from/to the
server. No other disturbing processed were running on the server.
The best result in transferring file were

Using Samba & Windows Explorer to copy
--------------------------------------
SERVER -> Win95 Workstation  40 sec
Win95 Workstation -> SERVER  16 sec
When doing this transfer, the LED from the network card is flashing from
time to time (0.2 sec on, 0.4 sec off), the average load of the hub is
about 5% and the "collisions LED" is on merely all the time.


Using Win95 ftp
---------------
SERVER -> Win95 Workstation 12 sec
Win95 Workstation -> SERVER 24 sec
When doing this transfer, the LED from the network card is flashing all
the time , the average load of the hub is about 40% and "colisions LED"
blinks from time to time.

Using Linux ftp from a Linux Worksation, I got the same 12 sec when
transferring file (approx 2.2 Mbytes/sec) . the HUB load was 40% and
very rare collisions.

PARAMETERS INVOLVED IN PERFORMANCE
----------------------------------
read raw - extremely important, when off, transfer time was 3 minutes
for the same file
TCP_NODELAY - very important , when off , transfer time was 1 minute
max xmit - important , 10-20 sec variations
read size - not very important (5-10 sec variations)
read ahead - not very important

Also, I have modified DefRecWindow in the [MSTCP] section of SYSTEM.INI,
TCPWINDOWSIZE : transfer time is bigger, sometimes even double.

++++++++++++++++++++++++++++++++++++++++++++++++++
First of all, I was tempted to say that the Microsoft TCP/IP protocol
has a bad implementation on Win95, but after trying the ftp transfer , I
could not say that any more.
At the begining, Linux server accepted ping packets larger than 32K
(even 48k) with an average trip of 150 ms. Window 95 workstation did not
accept ping packets larger than 3k. After modifying DefRecvWindow and
TCPWINDOWSIZE in [MSTCP] in SYSTEM.INI, Win95 has accepted "large ping
packets" but the performace was the same.

Even between 2 Linux computers, transferring by ftp the file at 2.2
Mbytes/sec isn't well enough. With a 4 Mbytes/sec I would be satisfied.

Do you have any idea how I could enhance Samba's performance in this
situation ?

Thanks for your patience,

-- 
Constantin Teodorescu
FLEX Consulting Braila, ROMANIA