VNC: Difference between revisions

Graham has dedicated VDI nodes collectively known as gra-vdi.  These nodes provide a full graphical desktop, accelerated OpenGL, and shared access to Graham's <code>/home, /project,</code> and <code>/scratch</code> filesystems.

To connect to gra-vdi, start your desktop VNC viewer (tigervnc) and enter <code>VNC server: '''gra-vdi.alliancecan.ca'''</code>. This will bring up a login screen where you can enter your Alliance credentials.  A desktop session will then be started on either gra-vdi3 or gra-vdi4 using a round robin algorithm.

You also have the option to connect to either machine directly by entering <code>VNC server: '''gra-vdi3.sharcnet.ca'''</code> or enter <code>VNC server: '''gra-vdi4.sharcnet.ca'''</code>. You might choose to do this if you find one machine is responding poorly due to heavy load, or if you want to use your local $SCRATCH directory on either server.  $SCRATCH points to /local/tmp/$USER on each machine. This is notably different than the clusters where $SCRATCH points to the shared directory /scratch/$USER location on all compute and login nodes.  Similar to the clusters, however, any data left under $SCRATCH on gra-vdi will eventually be deleted since the disc space is limited.

As with regular login nodes, the VDI nodes are a shared resource and not intended for doing batch computation. That is what the compute nodes are for.  Please only use them for graphics-related tasks, such as mesh generation, visualization, or using an integrated development environment (IDE).

 

If you want to perform computational tasks within a GUI, please do so on a cluster compute node using the <code>salloc</code> command as described in the Compute Nodes section below.  This will ensure the memory and CPU resources on gra-vdi are fully available for interactive graphical visualization purposes by other users when needed.