Samba speed question

[YJ Hong]

Hi All, 

I'm currently working on a feasibility study of using
Samba as video server which 
allows the MPEG videos on the Linux server to be
mapped out as network drives
on Window 98 clients, and then to select & play back
these video files by 
multiple clients concurrently.

My experiment so far showed smooth playback when the
source MPEG is of about 
450Kbits/s, beyond that I've tried MPEG of 1.2Mbits/s,
and experienced delays 
during playback, i.e. a 5 minutes MPEG would take
nearly 10 minutes to finish play, 
with jitters inbetween. The test of file copy from the
Samba mapped drive to the 
Window's local disk showed about 1.2Mbits/s transfer
rate.

My samba installation is from the latest release, I've
also edited the "smb.conf" to
include most of the recommended tuning according the
"Speed.txt" document
included in the release. It looks like either some
network configuration on either
the Windows client side or the Linux side were not
optimized, or that I'm having
a crappy Linux box (it's a Compaq Presarrio 5522 with
64MB RAM, ...)

Specific questions that I have are:
1. Using the "ifconfig" showed that my eth0
interface's MTU has maximum upper
bound of 1500. When I changed the MTU down to 600, the
samba transfer
really slowed down terribly. So, I'd assume that
getting improvement on MTU
can help. Is it that I need to get a better Ethernet
card to have a better MTU?
Or that MTU 1500 is the limitation generic to Linux?
2. On the same clinet/server pair a ftp test showed
about 2.2Mbits/s transfer rate,
which is not too exciting either for the two only
machines on a 10BaseT 
connection. Could it be that I'm having full/half
duplex setting problem on 
either the Windows or the Linux side? How to check it
out?
3. Or, the Linux server is simply too weak for it. I'd
like to have the Linux Samba
server serving up to 8 (eight) Windows clients for
retrieving of MPEG-1 files 
(1.2Mbps to 1.5Mbps bit rate MPEG-1) CONCURRENTLY and
hoping to have
all 8 MPEG-1 files played back smoothly. Certainly I'd
need to switch to 100BaseT
support on the Linux box side, what about the CPU, RAM
and disk configuration?
Specifically:
3.1 How good should the CPU be? Would multiple CPU
Linux help in this case?
3.2 What's the main memory minimal requirements?
Considering the Samba
supporting up to 8 concurrent clients?
3.3 RAID probably can help to improve the disk IO? Any
recommendation on
cost-effective RAID configuration for Linux for this
purpose (I'd assume that
RAID3 is good for large chunk mostly read-only)?
My sincere thanks in advance for any kind advice on
any of the above questions
from anybody. 
Cheers, YJ Hong
---------------------- 







__________________________________________________
Do You Yahoo!?
Yahoo! Mail - Free email you can access from anywhere!
http://mail.yahoo.com/