samba - Sep 2016 - Multichannel working at half speed with 2x NICs

Hi Jeremy,

Is it safe to assume it's just "strace -p <pid>", for the
running samba
daemon?
Regards
Kanchana

On Wed, Sep 28, 2016, 1:00 PM Jeremy Allison <jra at samba.org> wrote:
> On Wed, Sep 28, 2016 at 05:56:24AM +0000, Kanchana Marasinghe via samba
> wrote:
> > Similar to another thread that was posted recently (archive:
> > https://groups.google.com/forum/#!topic/linux.samba/sRvmCb25U_s)
I'm
> trying
> > to get multichannel working with a virtual Linux server running
version
> > 4.4.5.
> >
> > Output of 'uname -a': "Linux filehost 4.4.0-38-generic
#57-Ubuntu SMP Tue
> > Sep 6 15:42:33 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux"
> >
> > I have two VirtIO NICs on my server that I've confirmed works at
at
> least 1Gbps
> > (via iperf) to my Windows 10 client which also has 2 1Gbps NICs. Since
> virtio
> > interfaces dont seem to report link speeds, I've changed my
smb.conf to
> > reflect this as such:
> >
> > "interfaces = 192.168.1.120;speed=1000000000
> 192.168.1.118;speed=1000000000"
> >
> > I've also tried with and without "aio read size = 1" and
"aio write size
> > > 1", but that didn't change anything. In addition,
I've tried all the
> > suggestions in thread linked above and all have been unsuccessful.
> >
> > I've verified that all my drives on both the server and client are
> capable
> > of sustaining read/writes of well over 250MB/s, so I don't think
this is
> a
> > disk bottleneck issue.
> >
> > What happens during a file transfer is that both interfaces are only
> > utilized at around 50%, so they both combine to give me ~1Gbps, when
they
> > really should be working at 100% each for ~2Gbps total.
> >
> > What can I do to troubleshoot this?
>
> strace the connected smbd to ensure it's using the pthreadpool.
>

On Wed, Sep 28, 2016 at 07:45:03PM +0000, Kanchana Marasinghe via samba
wrote:
> Hi Jeremy,
> 
> Is it safe to assume it's just "strace -p <pid>", for
the running samba
> daemon?
http://lichtman.io/strace-an-existing-multi-threaded-process/

Sorry for the delay Jeremy. I ran strace on the lowest pid for smbd (I ran
"pidof smbd" to get pids, and used the lowest one of the 4 or so that
came
up).

Command was "strace -f -o strace.log `ls /proc/2019/task/ | xargs -n 1 echo
-n " -p`". I then copied a 1.3GB file from the server to my client to
generate traffic. The resulting file was around 93k lines (15MB). I've
copied the first 2000 lines since it looks like the rest are
repeats/similar: http://pastebin.com/raw/2EJsk0An

I can provide the full file as well if required.

On Wed, Sep 28, 2016 at 1:54 PM Jeremy Allison <jra at samba.org> wrote:
> On Wed, Sep 28, 2016 at 07:45:03PM +0000, Kanchana Marasinghe via samba
> wrote:
> > Hi Jeremy,
> >
> > Is it safe to assume it's just "strace -p <pid>",
for the running samba
> > daemon?
>
> http://lichtman.io/strace-an-existing-multi-threaded-process/
>