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- - VNC over SSH - too slow! (https://www.linuxquestions.org/questions/fedora-35/vnc-over-ssh-too-slow-578955/)

VNC over SSH - too slow!

I have configured my /etc/sysconfig/vncservers file on hostname.domain.com as:

Code:

VNCSERVERS="1:jameson"

VNCSERVERARGS[1]="-geometry 1280x1024 -nohttpd -localhost -depth 8 -nolisten tcp"

The server is running as:

Code:

bash$ ps aux | grep Xvnc

jameson  23992  0.0  0.1  46148  5572 ?        S    07:57  0:00 Xvnc :1 -desktop hostname.domain.com:1 (jameson) -auth /home/jameson/.Xauthority -geometry 1280x1024 -depth 8 -rfbwait 30000 -rfbauth /home/jameson/.vnc/passwd -rfbport 5901 -pn -localhost -nolisten tcp

When I try to access my display on hostname.domain.com:1 by:

Code:

client-bash$ env DISPLAY=client.thisdomain.com:0 ssh -X hostname.domain.com

server-ssh$ vncviewer localhost:1

at which point I get this on the stdout:

Code:

TXImage: Using default colormap and visual, TrueColor, depth 24.

the display that comes up is intolerably slow (refreshes a few small sections per second.) I know I have the bandwidth to do this without SSH, as I have been using it previously at 16 depth and it was quite quick.

What is going on here! Why is it so slow, and what is the TXImage message which suggests I am not receving 8-bit depth on the viewer?

Using the -via option of vncviewer solved this problem. Still not sure why the -X ssh forwarding option was so slow --- the vncviewer -via probably invokes some compression the ssh -X option does not.

I would suggest NX or freenx, which is much faster than X or VNC but then you can only connect from a windows/linux machine to a linux machine. Also the fedora scripts to set these up are broken and you have to run the script, find which lines give you an error and correct those.

dilip

Disable your wallpapers (maybe use just flat black)

Code:

Also in /etc/ssh/sshd_config

Compression yes

Code:

On your local machine

/etc/ssh/ssh_config

Compression yes

Also
VNCSERVERARGS[1]="-geometry 1280x1024 maybe to much resolution over vnc

Maybe 1024x768