[daip] AIPS across VNC ?

[Eric Greisen]

Nissim Kanekar writes:

 > On Fri, 16 Mar 2007, Eric Greisen wrote:
 > 
 > > Nissim Kanekar writes:
 > > >
 > > > Hi Eric,
 > > >
 > > > I'm trying to run AIPS across a remote VNC connection (which is much
 > > > faster than a direct ssh-based display across the net) but have run into a
 > > > problem with the display variables, with the TV, MESG and TEK servers not
 > > > opening at all. The problem seems to lie in the TVDISP, etc, variables,
 > > > when the DISPLAY variable is hostname:N, as is the case for a VNC
 > > > connection. I've tried forcing the TVDISP, TVHOST, etc to hostname:N, but
 > > > they seem to get re-assigned to :0 in the START_TVSERVERS script. Was
 > > > wondering if you happen to know a way around this.
 > > >
 > >
 > > I need to understand better what you mean here.
 > >
 > > I am assuming you are sitting at desktop and want to compute on
 > > server.  Does desktop run aips?  In other words are tasks on server
 > > talking to XAS on desktop or to XAS on server with display on desktop?
 > >
 > > Given that I have never heard of VNC it is totally not suprising that
 > > this does not work.  What command are you using to start aips?
 > >
 > > Eric Greisen
 > >
 > 
 > Hi Eric,
 > 
 > VNC stands for Virtual Network Computing; it essentially allows for 
 > desktop sharing, by the transmission of mouse and keyboard events from one 
 > computer to another. So it's a situation where I'm sitting on a desktop 
 > and want to compute at a server but the server desktop is displayed on my 
 > machine and keyboard/mouse events on mymachine are interpreted as 
 > keyboard/mouse events on the server. The effect is that tasks run on the 
 > server and also speak to XAS the server; however, the server display is 
 > not to HOSTNAME:0 but to HOSTNAME:N, where N is the VNC number (usually 1, 
 > if only one VNC connection is running).
 > 
 > I've tried using "aips" to start AIPS and also "aips tv=server:server", as 
 > I want to display the XAS on the server and not on my desktop. The first 
 > fails because AIPS tries to set up the XAS display on my desktop across 
 > the internet link while the second fails because :0 isn't an allowed 
 > display over a VNC connection.
 > 
 > The reason for using VNC over regular SSH-based displays is that it's 
 > infinitely faster than the latter. I regularly use it to analyse my GBT 
 > data on a GBT machine and to work in Socorro, while I'm away; the only 
 > thing that doesn't seem to work is AIPS, probably because the TVDISP, 
 > TVHOST and HOST variables are forced to HOSTNAME:0.
 > 

You are asking an awful lot of the aips startup script to understand
all these permutations.  I believe that it does in fact but not when
you use the one Inet XAS available to the server machine.  Make sure
that $DISPLAY is <server>:n  (n > 0) and then do
           aips tv=local
this uses the display variable as set and runs XAS locally on the
server.

Eric Greisen