what is the limit on number of concurrent Xvnc servers?
Wed Apr 16 09:06:01 2003
> -----Original Message-----
> From: Mike Miller [mailto:firstname.lastname@example.org]
> I'm running eight Xvnc servers right now, for eight different users, on my
> Solaris machine. Is there a limit on the number of concurrent Xvnc
> sessions that can be running?
Most restrictive limit: Xvnc is an X11 server which is limited to 64
instances: Display :0 trough :64 which uses ports 6000 trough 6063.
Applications and libraries can be restricted to this number. The next limit
in X11 is the display number that might be restricted to 2 digits, limiting
the display from :0 to :99, using ports 6000 to 6099.
The vnc port number should not be a restriction since any port can be used.
However, if the automatic rfb-port-number-assignment is used, be extreemly
carefull with numbers over 99 since with display :100, you will use port
6000 for rfb which is most likely already in use for X11 communication for
> I see that Xvnc uses ports in the 5901-5999 range and the applet is served
> from ports in the 5801-5899 range. That seems to imply an upper limit of
> 99 concurrent Xvnc servers. Is that true, or is there a way
> around it?
Yes, it is true, even worse as I describe above. However, with the usage of
the available options, you can use more.
> I'm wondering about upper limits because I'm thinking about buying a Linux
> machine with 8 GB of RAM and letting many users run VNC.
> Does anyone have any experience with that sort of setup?
If you like to provide vnc for 'normal' usage, best use the vnc setup as on
http://www.sourcecodecorner.com/articles/vnc/linux.asp. That keeps the
system clean from stale (not used) vnc sessions and has many other
- no need to configure on a per-user base
- users can select their geograpy on the fly (by connecting to the right
- no hanging sessions
and maybe even more.
Disadvantage: no 'resume', no shared sessions. The html-java viewer is
possible but has a flaw: the session is killed as soon as the browser looses
the connection. Hence not useable for normal usage.