FAQ: Using the NEX Computing Resources

Q. Why do I have to enter my password and other credentials twice when logging on to the supercomputer?

The supercomputing environment is protected from abuse by non-authorized users with a two-factor authentication method.

First, a user needs to log in to a Secure Front End (SFE) machine, then from there to a Pleiades Front End (PFE) or other machine in the NAS enclave. This can seem like a lot of overhead for gaining access to your own account, but there's a step you can take to reduce this overhead, called "SSH passthrough." SSH passthrough allows you to log into any system in the enclave by typing just one SSH command. With SSH passthrough you "pass through" the SFE directly to a NAS high-end computing system where you will do most of your work. To set this up, follow the instructions here carefully. Afterwards, you'll just enter your credentials once every time you access the NAS enclave -- no need to go through an SFE.

Q. Can I ssh into the NEX Computing system using Putty on my Windows laptop, or do I need a static IP for that?

A. You can ssh using PuTTY from your Windows laptop, but note that PuTTY will not allow you to export a graphic window. Better connect through an Xterminal emulator (i.e., Cygwin, Hummingbird, VMWare are some of the softwares that would allow that).

Q. Do the supercomputers run solely on command-line Unix platforms? I would prefer being able to run software like R through their Graphical User Interface (GUI).

A. The NEX computing platform is a Linux environment and you will need to know some basic bash scripting to at least set up your environment. You can call load the GUI of software such as Matlab and R directly from the linux environment if you export the remote desktop. More details and how to export your remote desktop can be found at the NAS Knowledge Base.

Q. Can I run a Microsoft Windows front-end on the NEX computing platform?

A. For the time being you will not be able to load and run a Microsoft Windows front end, but this may change in the future. However, you can have a remote desktop by installing KDE along with VNC.