The VirtualRDC is a cluster of Linux servers at Cornell University. In order to obtain access, you need to request a login. Contact the VirtualRDC administrators (virtualrdc@cornell.edu). Note: the VirtualRDC shares no account management with any other Cornell site, including other sites at CISER.
The VirtualRDC includes both 32-bit (Xeon) and 64-bit (Itanium) servers. The servers' primary purpose is to provide a computational environment to support replicating results using synthetic data produced within the Census RDC and released to the VirtualRDC. The servers also have a function as development environment for applications and programs to be used within the RDC network on the large Itanium-based servers.
The only way to access these systems is by SSH, a secure protocol that serves as a replacement for the old telnet. SSH provides security at both the login process and the actual terminal session, both of which are encrypted. It can also provide compression, accelerating any transfers made via SSH. Finally, it allows the creation of ``tunnels'', a method of transferring data between two systems that use other protocols. This is similar to VPNs (Virtual Private Networks) on a per-application basis.
Linux offers graphical desktops similar to Windows. The most commonly used are Gnome (www.gnome.org) and KDE (www.kde.org). The VirtualRDC provides KDE only. Modern implementations of these have often achieved a stability and user-friendliness similar to, but not quite reaching the standards of Windows or Mac desktops. When using the CISER Linux servers, you have the choice of restricting yourself to the command-line, or using a graphical interface.
In the remainder of this document, we will describe how to use a graphical VNC desktop on the Linux machines, either by the default and easier NX method (Section 1.5), or the somewhat more involved SSH+VNC method (Section 1.6) when NX cannot be used. Both connnection methods rely on SSH for the underlying connection, although this is transparent to the user of NX.