[Nottingham] Re: Two X servers on one X client, previously (no subject)

[Robert Davies]

On Wednesday 06 Aug 2003 19:20, David Bean wrote:
> On Tue, 2003-08-05 at 11:29, Jon Masters wrote:

> Xinerama, as far as I can tell, will only link two screens in one
> machine to make a display, not link two displays in seperate machines.
> What I want is to be able to see it like one big desktop, but from two
> machines.

I'd be surprised if you can do it, because an X-server has local control of 
keyboard, mouse and graphics display, but the remote networking protocol of X 
is designed for clients, not low level server <-> hardware comms.

It would be possible to create network drivers, the graphics and input 
equivalent of NBD (Network Block Device) for disk devices, which worked 
remotely over a network, but AFAIK there's no kernel support for this.  ATT's 
RFS offered remote device access over TCP/IP, though not only throughput 
10MB/s max would be an issue, but the latency, which would be orders of 
magnitude higher over ethernet than with H/W interrupts.

I think your best bet to get the effect you want is to either install a 2nd 
PCI graphics card in desktop machine, or (better) a new AGP graphics card 
that XFree supports in Dual Head operation.  Configure your  server machine 
to use a serial console and connect it to the desktop using serial ports with 
null modem cable (Laplink cable between COM ports in PC speak).  Then you 
choose the Xinerama option for one big display, or one of the other options 
available if preferred.

If you had a USB keyboard / mouse, or a PS/2 to USB adaptor you'ld also have a 
choice, to connect two seperate keyboards, mice and screen attached to same 
computer, should 2 ppl ever want to work on the machine, though it might 
require 2 running X servers rather than one.

Rob