samba - Jun 2007 - Vista client / Linux server - high browsing latency

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Hi,

I have the following system set up:

Server: Ubuntu 7.04, Samba 3.0.24,
  http://www.esuna.co.uk/~jay/misc/smb.conf

Client: Vista Ultimate 64-bit, NetBIOS over TCP/IP disabled, LMHOSTS
lookup disabled. Share mapped to drive Z:.

Up until a few days ago this was working fine. Read/write transfer rates
of over 20MB/s onto a RAID-1 array, speedy browsing. But yesterday I
noticed a drop in browsing latency; there's now a short but noticeable
delay before directory listings appear. Cygwin's ls (which I assume was
inefficient to begin with, but quite usable) takes 9 seconds to list a
small directory.

Curiously, *read/write throughput hasn't changed* - it's still
>20MB/s.
Latency also seems normal if I reboot into an XP Professional
installation, or access the share from my Vista Business 32-bit laptop
on the same network. The problem briefly seemed to fix itself yesterday
after I tweaked the configuration file a bit, but returned to poor
performance later in the day; possibly after a reboot but I don't recall.

I've upped the log level and can't see any obvious errors in log.smbd or
in log.(host). Observing traffic with tcpdump turns up nothing obvious -
the exchange goes on for longer but the difference in per-packet latency
isn't visible (Samba sure sends a *lot* of packets to list a directory).

Any ideas what I could do to trace this problem?

Thanks,

- --
Jay L. T. Cornwall, http://www.esuna.co.uk/~jay/
PhD Student
Imperial College London
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Jay L. T. Cornwall skrev:
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>
> Hi,
>
> I have the following system set up:
>
> Server: Ubuntu 7.04, Samba 3.0.24,
>   http://www.esuna.co.uk/~jay/misc/smb.conf
>
> Client: Vista Ultimate 64-bit, NetBIOS over TCP/IP disabled, LMHOSTS
> lookup disabled. Share mapped to drive Z:.
>
> Up until a few days ago this was working fine. Read/write transfer rates
> of over 20MB/s onto a RAID-1 array, speedy browsing. But yesterday I
> noticed a drop in browsing latency; there's now a short but noticeable
> delay before directory listings appear. Cygwin's ls (which I assume was
> inefficient to begin with, but quite usable) takes 9 seconds to list a
> small directory.
>
> Curiously, *read/write throughput hasn't changed* - it's still
>20MB/s.
> Latency also seems normal if I reboot into an XP Professional
> installation, or access the share from my Vista Business 32-bit laptop
> on the same network. The problem briefly seemed to fix itself yesterday
> after I tweaked the configuration file a bit, but returned to poor
> performance later in the day; possibly after a reboot but I don't
recall.
>
> I've upped the log level and can't see any obvious errors in
log.smbd or
> in log.(host). Observing traffic with tcpdump turns up nothing obvious -
> the exchange goes on for longer but the difference in per-packet latency
> isn't visible (Samba sure sends a *lot* of packets to list a
directory).
>
> Any ideas what I could do to trace this problem?
>
> Thanks,
>
> - --
> Jay L. T. Cornwall, http://www.esuna.co.uk/~jay/
> PhD Student
> Imperial College London
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>   
Which one of your computer is master browse?

-- 
Rune T?nnesen
Bedste Hilsner/Best Regards

>>>Observing traffic with tcpdump turns up nothing obvious -
>>>the exchange goes on for longer but the difference in per-packet
latency
>>>isn't visible
You can do the similar tracing on the client side using ethereal/wireshark.
Filter out for smb packets and see which smb request/response is taking
maximum time, to track down the problem.

-- 
Aravinda
(Views expressed here are my personal opinion ONLY)