[YLUG] user mode linux and slirp

[Liam Wilson]

Hi

The value of MTU doesn't seem to have any effect on
the upload speed, its currently set to 1500.

I did notice that if I copied several files
simultaneously from the virtual machine to the host
machine, with scp, each instance of scp recieved the
same amount of bandwidth that it would recieve if I
had run them separately. For some reason each
connection is recieving a fixed amount of bandwidth
rather than the maximum available bandwidth.

Liam
--- Gaffer <derrick_s at tesco.net> wrote:

> Hi Liam,
> 
> On Wednesday 24 January 2007 13:37, Liam Wilson
> inscribed thus:
> > If only it were that simple! The version of slirp
> I
> > have does not allow me to set the baudrate as it
> is
> > supposed to run at the maximum possible rate.
> >
> > Could this be something to do with incorrect
> > configuration of the network on the virtual
> machine?
> > If run ifconfig I get:
> > eth0      Link encap:Serial Line IP
> >           inet addr:10.0.2.15  Mask:255.0.0.0
> >           UP RUNNING NOARP  MTU:1500  Metric:1
> >           RX packets:27 errors:0 dropped:0
> overruns:0
> > frame:0
> >           TX packets:26 errors:0 dropped:0
> overruns:0
> > carrier:0
> >           collisions:0 txqueuelen:256
> >           RX bytes:3176 (3.1 Kb)  TX bytes:3601
> > (3.5Kb)
> >           Interrupt:5
> >
> > lo        Link encap:Local Loopback
> >           inet addr:127.0.0.1  Mask:255.0.0.0
> >           UP LOOPBACK RUNNING  MTU:16436  Metric:1
> >           RX packets:4 errors:0 dropped:0
> overruns:0
> > frame:0
> >           TX packets:4 errors:0 dropped:0
> overruns:0
> > carrier:0
> >           collisions:0 txqueuelen:0
> >           RX bytes:336 (336.0 b)  TX bytes:336
> (336.0
> > b)
> > If that sheds any light?
> >
> > Liam
> >
> > --- Paul Gibbs <paul-listmonkey at pacem.plus.com>
> wrote:
> > > I can tell you why it's slow (IIRC), but not how
> to
> > > fix it...
> > >
> > > slirp recognises the importance of lo latency,
> it
> > > also knows that many
> > > serial interfaces have large buffers and so does
> its
> > > own rate limiting.
> > >
> > > I'm surprised that you get 64KB/s I'd expect it
> to
> > > limit by default to
> > > 64Kb/s.
> > >
> > > Anyway you just need to find the correct
> > > parameter....
> > > ...and a quick Google says, (from
> >
> >
>
http://www.cs.ualberta.ca/doc/Software_manuals/slirp.doc.txt)
> >
> > > to call
> > > slirp with -b big-number-in-bits/s
> > > Go to '8. Setting the "baudrate" Option' within
> that
> > > document for more
> > > details.
> > >
> > > Paul.<><
> > >
> > > Liam Wilson wrote:
> > > > Hi
> > > >
> > > > I've just been playing around with user mode
> > >
> > > linux.
> > >
> > > > I've got myself a slackware 10.2 virtual
> machine
> > >
> > > which
> > >
> > > > I'm trying to use with slirp networking. I
> start
> > >
> > > the
> > >
> > > > machine with:
> > > >
> > > > vmlinux ubd0=root_fs eth0=slirp,,path/to/slirp
> > > >
> > > > One booted I bring up the network with:
> > > >
> > > > ifconfig eth0 10.0.2.15 up
> > > > route add default dev eth0
> > > >
> > > > In my .slirprc file I have the line:
> > > > redir tcp 5555 22 ie to allow me to ssh into
> the
> > > > virtual machine.
> > > > The problem is that data transfer from the
> machine
> > >
> > > is
> > >
> > > > very slow (about 64KB/s). I have the fullbolt
> > >
> > > version
> > >
> > > > of slirp from slirp_1.0.17-1_i386.deb which
> should
> > > > work at full speed. This only affects data
> > >
> > > transfer
> > >
> > > > from the machine, when transfering data to the
> > >
> > > machine
> > >
> > > > I get about 2MB/s. Does anyone know a fix for
> > >
> > > this? I
> > >
> > > > was trying to run X applications on the
> machine so
> > >
> > > I
> > >
> > > > need as much bandwith as possible.
> > > >
> > > > Thanks
> > > > Liam
> 
> Just guessing.  Anything to do with MTU ?  1460
> maybe !
> 
> -- 
> Best Regards:
>              Derrick.
> 
> _______________________________________________
> York mailing list
> York at lists.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/york
> 



 
____________________________________________________________________________________
Yahoo! Music Unlimited
Access over 1 million songs.
http://music.yahoo.com/unlimited