Poor Samba throughput on 6.0

Jeremie Le Hen jeremie at le-hen.org
Tue Nov 8 22:09:55 PST 2005

Hi, Joao,

> 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?

I won't be able to help you much, but as almost nobody answered you,
I take it for the moment in order to ask you some more informations.

Which scheduler are you using, 4BSD or ULE ?  It might be worth testing
the other one and sending us the new benchmark results.

Also, if you are able to remove a drive from your RAID5, you can try
R/W performances from/to it, without using amr(4), both with 4BSD and

Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >

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