Summary

We will be replacing our VNC servers with new hardware running on TOSS4. This bulletin impacts all users who connect to LC via VNC Viewer. VNC users should prepare for the changes explained below.

The new CZ & RZ VNC servers are already accessible for those who want to transition immediately; the current CZ & RZ VNC servers will be turned off on December 15, 2023.

Update 12/22/2023 The TOSS4 migration for `scfvnc`, our VNC server on the SCF,, has been delayed until the week of January 29. Along with a move to TOSS4, `scfvnc` will start to use the Session Manager software already in use on the OCF.

Changes

As of 12/15/2023, connections to

czvnc.lln.gov:5999

rzvnc.llnl.gov:5999

will route to new hardware on TOSS4. ("Old" VNC hardware is running TOSS3.) This change of hardware and operating system will mean

  • Any sessions hosted on the old server will be permanently deleted.
  • Users will need to upgrade their VNC Client to newest version to take advantage of new features, such as dynamic resolution, and stability fixes.
  • Lustre will be inaccessible from TOSS4 VNCs.
    • VNCs will not directly mount lustre.
    • VNC should therefore be more stable when lustre issues occur.
  • The KDE desktop —including the Konqueror browser — will no longer be available from VNC.
    • We cannot support KDE in TOSS4 because it is not supported by RHEL 8.
    • If you have any custom xstartup files that reference KDE, either these references or the files themselves will need to be removed.

The login procedure for `czvnc` and `rzvnc` will remain the same.

Update 12/22/2023 

The TOSS4 migration on the SCF starting the week of January 29 will terminate user sessions on `scfvnc`, forcing users to create new sessions in VNC Viewer. After the TOSS4 migration, the login procedure on `scfvnc` will match that of `czvnc` and `rzvnc`; Session Manager software will track user sessions and, after login, users will see a few options including to connect to an existing session or start a new session. Users will still connect to

scfvnc.llnl.gov:5999

Transitioning early

Sessions on the new VNC hardware can be started prior to 12/15/2023 by connecting to

newczvnc.llnl.gov:5999

newrzvnc.llnl.gov:5999

from VNC Viewer.

During the transition period (now until 12/15):

When you connect to either `czvnc` or `newczvnc` in VNC Viewer, the “Connect to” screen that appears after authentication will offer you pre-existing connections from both `czvnc` and `newczvnc`. You will get error messages or other odd behavior if you try to connect to a session created on `newczvnc` from `czvnc` or vice versus.

Impact

Update 12/08/2023 

All OCF (CZ & RZ) and SCF users who use RealVNC’s VNC Viewer to connect to LC systems will be impacted.