Poor Samba throughput on 6.0

[Joao Barros]

Hi,

Last month I started a thread[1] on current@ about this, but I guess I
should have done it here, my apologies for that.

After my initial post I did some more testing and I'm going to start
clean here with all my findings :)

I started with Samba 3 installed on a PIII 733MHz with fxp (82559) and
a RAID5 consisting of 4 drives connected to an amr.
Performance reading or writing was poor, around 5.5MB/s measured on
two Windows clients and iostat never topped that by much.
cpu was mbufs were available and there were no IRQs shared.
To dismiss the amr out of the question I tried with a local IDE
attached yielding the same results.
I then tested the same on a machine I have at work, an HP Proliant
server, Pentium 4 3.06GHz, used SMP instead of GENERIC to use HTT.
I could get 8MB/s with 2 read or write simultaneous operations. With 1
operation I still can only get 6MB/s
This machine has 1GB ram and after copying a 700MB file to it it was all cached.
A copy to dev/null took 1 second.
A copy via samba took the same time as if there was no cache for it.
iostat always showed 0.0 during the operation so that pretty much
takes disks, controllers, IO out of the picture.

Both machines have cpu, IO and mbufs to spare and they still can't use
them. Why?


[1] http://lists.freebsd.org/pipermail/freebsd-current/2005-October/057116.html

--
Joao Barros