Connecting to Zrek

Connecting to zCSF (Zrek) – Summary

Once you have been given an account the two steps to accessing zrek are:

1. Use an ssh program to log in to

   zrek.itservices.manchester.ac.uk

   using your central IT username and password (same as used for email).

2. Then, from the zrek login node, use the batch system to access the backend compute node that provides the GPU, Xeon Phi or FPGA that you require:
   • Use qrsh to access a backend node interactively (get a command-line on a node).
   • Use qsub to run a batch job on a backend node (traditional non-interactive batch job).

   For a full list of commands available to access the backend nodes, run the command

   backends

   on the login node.

Further instructions are available on connecting to the backend nodes.

Using the Research Virtual Desktop Service

Given the interactive nature of the zCSF we recommend use of the Research Virtual Desktop Service to access Zrek. The Virtual Desktop can be accessed from on or off campus (no need for VPN). From the Virtual Desktop you can then SSH in to Zrek.

• Applications on the zCSF that open a GUI are usually more responsive if they open it on to the Virtual Desktop rather than on to your local computer.
• The Virtual Desktop allows you to work from different physical locations without having to close your applications and re-open them between sessions.

Follow the Virtual Desktop instructions then SSH in to Zrek (see below).

SSH in to Zrek

As noted above you must use ssh to log in to the zCSF (zrek) login node. You can login to zCSF directly via SSH from a University campus PC or Wifi connection, or VPN.

If you are using the Research Virtual Desktop you’ll need to SSH in to Zrek from there.

SSH connection from Linux & OS-X

All user connections to zCSF are by means of an SSH client whether from the Virtual Desktop Service (preferred) or direct from your own machine. Linux and OS-X users will be able to login using OpenSSH, which comes with all popular distributions of Linux and with OS-X, by typing

ssh -X username@zrek.itservices.manchester.ac.uk
    #
    # ... UPPERcase X
    # ...replace username with your username (e.g., mpqrxyz8)

at the command-line.

Connecting from MS Windows

All user connections to zCSF are by means of an SSH client whether from the Virtual Desktop Service (preferred) or direct from your own machine. Users of a desktop or laptop machine running MS Windows should read the dedicated instructions (written for the CSF but apply equally to zrek) which detail how to:

• login to zrek (simply replace references to csf.itservices.manchester.ac.uk with zrek.itservices.manchester.ac.uk)
• upload and download files, and
• run graphical applications (including gedit, an editor similar to Notepad).

Logging Out

Once you have finished using the system you should logout (so as not to waste system resources and also for security reasons). You can log out by using either of the following commands:

• logout
• exit