[Samba] Speedup windows client [was] What is the maximum speed for download from a samba share

Knut Krüger itservice at knut-krueger.de
Wed Apr 25 06:28:50 UTC 2018

Am 22.04.2018 um 04:30 schrieb L A Walsh via samba:
> Knut Krüger via samba wrote:
>>> Limiting the linux-server's max cpu-speed had
>>> the most affect on performance:
>>> (limited to 1.6GHz instead of 2.4GHz) (33% limitation)
>> The server is equipped with an 6 core / 12 tread 3.6 GHz CPU (Intel 
>> Core i7-980x   and  a Raid 10 Disk array.
>> The cpu is 90% idle (including webserver traffic and mailserver 
>> traffic) during downloads.
> ---
>    In protocols before cifsV3, only 1 tcp connection was allowed between
> a user at workstation and a server.  So multi-cores make no difference.
Ok this clarifies why two downloads are getting more bandwidth than 1
>    When you say "the cpu is 90% idle", you realize that means 10%
> busy.  10% * 12 cores = 1.2 cores busy.  That may imply one
> core is "pegged".  Though it sounds unlikely even with a 100Mb
> network that your cpu is the problem.
To clarify the setup
The root server is the 6 core/12 tread machine.
it is an stretch proxmox installation
this machine is minimum 90% idle

one of the  virtual machine is the samba VM connected via VPN
Looking to the cpu usage of this VM ist nearly zero during downloads.
There is no difference wehter the VM gets 1 ore more cores or changing 
the CPU limit.  /CPU Limit us unlimited

doing some additional test, it seems that a part of the speed lag is 
client depending.

    4 core client with Linux is about 25.000 Kbits
    Lenovo Thinkpad T520 with Windows 7 is the worst client
    (unfortunately the most important) with 750 kbits/sec  :-(

So as a first step (as it is really important)  i have to speed up the 
windows client.
Any hints?

After that I will try to speedup the server.

Kind regards Knut
>    For my testing, I run my test script on cygwin and
> "cd" to my home directory on the server (/h) where my
> test "files" (character devices) are located (/h/zero and /h/null)
> From there I usually run it with "bin/iotest".  I'll attach
> the bash script.  If you find it of any use, great! else, ignore it.
> My linux-box has bash-4.4 on it and is currently using a 4.14.0 kernel.
> Good luck...don't want to overwhelm, so I'll end here.

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