[Samba] Slow perfomance comparing Win NT 4.0 server

Jeremy Allison jra at samba.org
Thu Jul 16 15:36:28 MDT 2009


On Fri, Jul 17, 2009 at 12:06:52AM +0300, Georgy Goshin wrote:
> Hello!
>
> I've replaced the old Windows NT 4.0 server with new modern
>
> (Core 2 DUO 2.4Ghz with 1GB RAM, SATA drives in linux software RAID 1 
> under CentOS 5, Samba 3.3.0-38)
>
> But client started to complain that the speed was slowed down. I made 
> some tests with old and new servers and see that working with files is 
> really slow. Office and pdf documents opening sometimes up to minute 
> comparing 1-2 second from old server.
>
> Please point me to the right way to catch the problem
>
> hdparm shows good numbers:
>
> /dev/md0:
> Timing buffered disk reads:  182 MB in  3.01 seconds =  60.48 MB/sec
> /dev/md0:
> Timing cached reads:   4528 MB in  2.00 seconds = 2265.41 MB/sec

This is not needed (and may be harmful)

       socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192

But this won't make a difference between 1-2 seconds and one
minute. Is it slow to initially connect to the share ? If
so I'd suspect DNS lookups. If it's slow accessing the share
but fast to connect I'd get a wireshark capture trace and
looks for timestamp gaps in the packet stream. That should
give a clue. You can do the same with a timestamped smbd
log at debug level 10 - look for suspicious gaps in activity,
as there's some "waiting" problem that's being triggered
here.

Jeremy.


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