I have an old Opensuse server (can’t access it at the moment remotely) I think it is V10 with KDE desktop.
I have had to move all our servers and that has meant taking them out of a rack and stopping using the rack mount monitor. I have replaced it with a normal old monitor. Both have used a KVM switch.
Everything is working except for VNC which just produces a black screen on the remote PC.
Presumably the resolution\refresh rate is different and that is a problem.
How do I get the VNC system to recognise the new monitor?
VNC has undergone many changes over the years, so your particular problem may (or might not) be specific to your version of VNC so you’ll likely have to provide more detail about your openSUSE version as well as the actual VNC version.
To display your VNC version, and assuming that it was installed from a package and not some other way
zypper info vnc
To identify your openSUSE version might be a bit tricky.
The following command works with today’s openSUSE but very, very old openSUSE used a different command
cat /etc/os-release
More than likely I would guess that changing your hardware shouldn’t affect your VNC, for a very long time Linux (including openSUSE) deploys a separate X server (or recently optionally a socket service) to support remote vs local connections… Local connections might be affected (ie connecting through a Unix socket) but X servers generally generally shield clients from hardware details. X servers themselves might require hardware configuration, but then I’d expect them to consistently work or not and I think you’re saying that some connections work without a problem.
In any case, there are so many risks and vulnerabilities associated with running an old, unsupported version of openSUSE that maybe you should consider installing a modern openSUSE side by side with your old system (if you have enough disk space), then consider all that might be required to migrate functionality to your new server over time… Done correctly, there should not be any risk to your original running system and if you run into migration issues (almost certainly you will run into many) you can work through those without any pressure or risk to your original system.
Thanks for that. I have seen that post many times today!
I have got to the server now and have done a lot more work. Its opensuse 11.4. I believe the problem is not associated with new monitor but with a change of the machine name the week before.
I am getting an error in the warn file which says:
kdm: Dell2950lw.domain.name:1 [5268] cannot connect to Dell2950lw.domain.name:1 giving up
where the domain.name is incorrect (old domain name)
then when vnc connection is attempted
kdm [1328] : Display Dell2950lw.domain.name cannot be opened
hosts, hostnames, dhcp, dns all correct. kdm is getting a fqdn name from somewhere that I can’t find. I am starting to wonder about X authority.
and I forgot to say that the vnc connections to SLES 11 and SLES 12 are all working perfectly and all machines have had the same domain name changes and monitor change. However the opensuse 11.4 server does run dhcp and dns because it was historically the first machine.
Replacing monitor cannot under any circumstances change system domain name. You obviously did much more than you told us.
So you apparently did change something in networking configuration as well. In which case you probably have to reconfigure your systems to use new correct domain name.
Well I thought that I had changed everything that needed to be changed but obviously I have missed something re KDE KDM because I have the error described above. Other than that there are no network changes, same IP addresses, same network hardware, same ethernet config.
I have reconfigured DNS and DHCP to reflect new domain name and every server is reporting the correct names.
I have searched the opensuse file system for the old domain name and there are are no obvious config files containing the old name.
I have been through all the startup files for the system and I can’t find anything.
Somewhere KDM is getting a name which is not the new hostname.
First,
You should consider upgrading or replacing your 11.4 machine, it’s extremely old and would likely cause problems, particularly if your network services (dns, dhcp) support network login services like samba, ad or ldap.
In fact, if your machine runs no other services, then I’d strongly consider replacing your 11.4 with a 15.1 machine running in a virtualization technology because services like dns and dhcp require almost no resources to service a small (or even medium) sized network.
Aside from issues about re-deploying…
You should know that the machine that supports and runs network services like DNS and DHCP do not typically don’t do lookups well to services running locally on the same machine, so may need to be setup to do a different kind of lookup (eg entries in /etc/hosts) and configuration (static address, not a dhcp client). In fact, if someone had already run into this issue long ago, you will likely find entries made long ago that’s still pointing to your old FQDN.
And, don’t forget to change your hostname in places like the Hostnames tab of your YaST Network Services module.
If you have configured your local machine with a reserved lease, that likely won’t work in this specific case (DNS for the network is running on this same machine).
You need to configure an actual static address and not use DHCP at all, if you do this consider the implications of configuring an address which is likely within your DHCP server’s scope or assigning a new address outside of your DHCP scope but within your network’s NetworkID (ie subnet mask range).
Do you have any non-default entries in your /etc/hosts?
If you have any entries and you’ve changed your machine’s network IP address, the entries likely point to your old address.
If you have no entries pointing to your LAN network address, you may want to create one to see if that solves your problem.