[Samba] Weird Samba upload performance on Gigabit network

[John Drescher]

On 11/9/06, David Harrison <david.harrison at stress-free.co.nz> wrote:
>
> Here's a weird one that may have nothing to do with Samba and more to
> do with network frame sizes.
>
> I have recently upgraded the network infrastructure to support
> gigabit speeds.
>
> - OSX Tiger to OSX Tiger file transfers operate at gigabit speeds.
> - Samba 3.0.23C (Suse 10) to OSX Tiger file transfers operate at
> gigabit speeds.
> - BUT OSX Tiger to Samba 3.0.23C (Suse 10) file transfers operate at
> 1-2meg/second which is well down from expected performance.
>
> The strange thing is if I begin a file transfer from OSX Tiger to
> Samba and in a terminal window on OSX begin an SCP copy operation to
> the same Suse server the file transfer speed of Samba jumps up to
> gigabit level speeds. As soon as the SCP copy operation is stopped
> the Samba file transfer process drops to 1-2meg/second again.


Looking at your numbers I believe that you have both network and samba
problems.

Can you run netperf or do some nfs testing?

Today I ran it and found out a few of my servers (using nvidia mobo
adapters) although the gigabit light was on the nic and the switch the
adapter was not transfering at gigabit speeds.  I did a nfs test like the
following:

dd if=/dev/zero of=/mnt/remoteserver/test.dat bs=16k count=16k

and got around 10MB/s which is only 100mbit speeds. On netperf I verified
that my maximum transfer rate was around 94mbit/s so I googled a bit and
then ended up upgrading my kernel to 2.6.18 and then did the same test and I
got 109 MB/s on netperf and on the nfs test above I got 43MB/s and after
setting nfs to asynchronous mode I got 57MB/s.

John