[Samba] ridiculous slow gigabit transfer, faster with VNC

Mark Baily mark16829 at gmail.com
Thu Jul 19 23:33:07 GMT 2007

I have checked the duplex setting in opensolaris and it has
autonegotiated with the switch at 1000Mbps (gigabit) and also
full-duplex. The switch itself has no means to query, it is an
unmanaged consumer switch.

On 7/20/07, Andrew Morgan <morgan at orst.edu> wrote:
> On Thu, 19 Jul 2007, Mark Baily wrote:
> > Hi,
> > I have a problem with file transfers between a windows systems and unix
> > systems.
> > I have one win32 desktop (intel e6400 2Gb Ram), one win32 laptop (p-m 2Ghz).
> > Also one linux laptop (p-m 1.4GHz) and one opensolaris desktop (intel
> > e4400 1GB Ram).
> >
> > The two laptops have built-in 100Mbit ethernet and desktops have 1Gbit
> > ethernet on the motherboard. Both desktops use a Marvell Yukon.
> >
> > The file transfer rate between two systems using FTP between the two
> > desktops (win32 to opensolaris) is consistently 50Mb/sec which is as
> > expected.
> >
> > Using scp I only get 5Mb/sec between from any win32 system to any unix
> > system, much slower than expected.
> >
> > Using scp from the linux lapotp to solaris desktop is 10Mb/sec as
> > expected (laptop has 100mbit only).
> >
> > Using samba to copy a 1GB file I get about 7 minutes from win32 to
> > opensolaris. From opensolaris to win32 the windows dialog says
> > estiamted time 142 mins. Using plain FTP it takes 25sec. This is very
> > consistent.
> >
> > A twist is that if a VNC client is open from the win32 desktop to the
> > opensolaris box the estimated transfer time via samba from opensolaris
> > to win32 drops right down to about 4 min. Much better, but still
> > nowhere near the FTP.
> >
> > I have also tried swapping between a D-Link DGS-1008D switch and a
> > Netgear GS105 switch with no difference.
> >
> > Since the FTP is very consistently acheiving 50megabytes/sec, I don't
> > think it can be blamed on a hardware fault.
> >
> > However the problem doesn't appear to be just samba either, as the
> > slowness also occurs with scp, albiet scp is much more consistent at
> > 5mb/sec than samba varying at 1GB/142min to 1GB/3min with VNC open.
> >
> > Is this problem something to do with TCP stacks playing up? What else
> > might it be?
> Have you confirmed that you do not have a duplex mismatch?  I don't know
> if D-Link or Netgear (consumer grade?) switches can be queried for the
> duplex setting or forced to full duplex.  Usually this stuff "just works",
> but the behavior you describe sounds very much like the switch is half
> duplex and the server is full duplex.
>         Andy

More information about the samba mailing list