[Samba] Transfer speed

[Jeremy Allison]

On Mon, Apr 09, 2012 at 01:36:22PM +0200, Emmanuel Florac wrote:
> Le Mon, 9 Apr 2012 10:17:25 +0200 vous écriviez:
> 
> > I'm almost sure than Samba can use almost full gbps speed but how to
> > enabled that ? :(
> 
> As I mentioned in my previous post, Samba can achieve full Gb speed
> easily but not with any client. Basically, Linux, Mac OS X and old
> windows (winXP, win2K3) can't achieve nearly as good performance as
> win7-64 or win2K8R2 (usually limited to 60-75% of the latter).
> 
> Another rule of the thumb I've determined is that you can achieve about
> half the raw disk throughput performance with samba. That means that if
> you can read-write locally at 120 MB/s, your samba performance will
> reach 60 MB/s but not much more. If you want 750 MB/s, you'll need a
> disk subsystem able to sustain 1.5GB/s.
> 
> Note that NFS sharing performs way, way better than CIFS under both
> Linux and Mac OS X. Mostly the same restrictions apply about relative
> disk and network performance, but any Unix box can saturate (115-120
> MB/s) a Gb link over NFS, both directions, given that your disk
> subsystem is about twice as fast as that.
> 
> From my experience, using modern hardware jumbo framing makes no
> difference for transfers across a limited number of machines, even over
> 10GigE ethernet (this is not the case for Gb hardware before 2005 and
> 10GigE hardware before 2010). OTOH proper framing makes a dramatic
> difference when using InfiniBand. 
> 
> So what does this mean for your setup? If you want to saturate your
> gigabit link, you'll have to use either several linux/XP/Mac clients,
> or 1 win7 or win2K8 client; you'll need fast enough disks (a single
> drive definitely won't do), and of course a fast enough machine -- but
> anything 64 bits capable definitely is.

Before this is taken as gospel :-), I think we should give
Steve French and Jeff a chance to chime in here on behalf
of the Linux CIFSFS client.

I think it's seen a lot of improvements recently w.r.t.
multiple outstanding reads/writes, but I'm not sure
what kernel version this went into.

I think Stevef thinks CIFSFS can give NFS a run for its
money at least Linux -> Samba.

Jeremy.