X: display remote session or "Can't open display"

DBabo · 07-04-2015, 02:29 PM

my infrequent use of X over ssh lead me to become horribly outdated in understanding of how to troubleshoot the problem.
For long years, the "export DISPLAY=myhost:0.0" and then after "oh, shoot" " xhost +*" were mostly working for me right away.

But now, i understand, that i have no idea, what is involved in making "X over ssh" work and how do i approach the troubleshooting.

If somebody can point me to the up-to-date article that explains the "Architecture" of the items involved, i'll appreciate it a lot.

For simplicity, lets just say that there are two PCs with RedHats distros, on the same network with iptables. Each PC has a few video cards.

// sorry, the celebration of 4th July and typing are on collision courses at the moment.

berndbausch · 07-06-2015, 01:28 AM

Quote:

Originally Posted by DBabo

my infrequent use of ssh over X lead me to become horribly outdated in understanding of how to troubleshoot the problem.
For long gone years, " export DISPLAY=myhost:0.0" and then after "oh, shoot" " xhost +*" were mostly working for me right away....

But now, i understand, that i have no idea, what is involved in "ssh over X" and how do i approach the problem.

If somebody can point me to the up-to-date article that explains the "Architecture" of the items involed, i'll appreciate it a lot.

Lets say i have two pcs with iptables, on the same network, with RedHats distros, several video cards.

// sorry, the celebration of 4th July and typing are on collision courses at the moment.

Slightly off-topic, but perhaps it helps. My problem was running X11 programs as root, which results in

Code:

Invalid MIT-MAGIC-COOKIE-1 keyUnable to initialize GTK: could not open display

This post helped me.