From: Axel Kohlmeyer (
Date: Tue Feb 27 2007 - 11:43:12 CST

On Tue, 27 Feb 2007, christopher wrote:

CB> This sounds like an xhost problem. You need to set the xhost before
CB> connecting and set the display after ssh'ing... Something like:
CB> xhost +
CB> ssh <servername>
CB> setenv DISPLAY <clientname>:0.0
CB> vmd

arrrrgghhh!!! please _never_ _ever_ use 'xhost +' on any
machine that is connected to the net.
this opens your x-display for _everybody_ (well, as far
as the next properly configured firewall). this way everybody
in the neighborhood can follow _every_ keystroke you're
doing and create snapshots of your screen, and....

please see the xauth man page on how to set up an
.Xauthority file and how to add access for individual
sessions to it, in case you are on a 'trusted' network
(data transfer is still clear text). or use 'ssh -X'
to have secure x11 forwarding.

the major problem with running OpenGL on a remote display
is that performance is very much limited (not to mention
tons of compatibility problems with vendor specific GL


CB> Ay■e Ízlem Sezerman wrote:
CB> > Dear VMD users,
CB> >
CB> > We cannot run VMD from a remote server. We have checked that the
CB> > installation in that remote computer is succesfully established. But
CB> > when we try to connect that remote host from a local computer via ssh
CB> > and try to run vmd we face an error message as follows "Cannot open
CB> > display: " . We have also checked than Open GL libraries are installed
CB> > to that remote. Have anyone faced a problem like this ?
CB> >
CB> > Thanks
CB> >
CB> > Ozlem
CB> >
CB> >
CB> >
CB> >
CB> >

Axel Kohlmeyer
   Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
If you make something idiot-proof, the universe creates a better idiot.