Connecting to Discovery Cluster

To use the Discovery Cluster you must have a basic working knowledge of Linux (RHEL/CENTOS 6).

A detailed tutorial and the preferred software to use (Oracle Virtual Box) is presented in a tutorial that you can download using the link: http://nuweb12.neu.edu/rc/wp-content/uploads/2013/08/LinuxTutorial.pdf. On Windows Desktops rather than using a windows ssh client like Putty and XMing (for X11 windows forwarding) it is recommended that Linux be installed using Oracle VM Virtual Box. The manual for this is here. After installing Virtual Box and Linux be sure to install the Virtual Box Guest Additions. This is further described in the Virtual Box Manual. The BIOS must have virtualization enabled (for Intel CPU’s VT-x and for AMD CPU’s AMD-V). Enabling Hyper-threading with Intel turbo-boost is optional but preferred. You can assign more cores to the VM if Hyper-threading is enabled, and you will be able to exploit faster speeds on Intel CPU’s if turbo-boost is enabled. Most BIOS’s have this configured by default so if you have issues be sure to check your BIOS.

The method to connect to the Discovery cluster is via ssh (secure shell). Linux/Mac Clients have a shell prompt from which to connect.

ssh -X or ssh -Y ensures X11 forwarding is enabled and you can launch windows/GUI’s from Discovery login nodes. An example login is shown below using your cluster account credentials which is your “myneu” username and password. Discovery cluster login authentication is done via Northeastern University Active Directory and you will only be able to login after your account application is approved by ITS Research Computing and the Research Computing Committee.

[nroy@nkr-rc-neu ~]$ ssh -X nroy@discovery.neu.edu
nroy@discovery.neu.edu’s password:
Last login: Thu Aug 22 12:45:58 2013 from 129.10.91.124
[nroy@discovery4 ~]$

To login from Windows clients directly we recommend using PuttY for ssh and Xming for X11 forwarding.

PuttY can be downloaded using the link: http://nuweb12.neu.edu/rc/wp-content/uploads/2013/08/putty.exe. Please note this is an executable and can be run directly.

Xming can be downloaded using the link: http://nuweb12.neu.edu/rc/wp-content/uploads/2013/08/Xming-6-9-0-31-setup.exe. This is an installation package and must be installed selecting all the default options. DO NOT CHANGE anything during the installation.

Connecting using PuttY and Xming to Discovery is given in detail in the document obtained using the link: http://nuweb12.neu.edu/rc/wp-content/uploads/2013/08/Connect_Discovery_Cluster.pdf

If you have issues using “discovery.neu.edu” when you ssh into the cluster you can directly opt for a login node. In this case replace “discovery.neu.edu” with “discovery2.neu.edu” or “discovery4.neu.edu” that will take you directly to a login node without using round-robin DNS.

If you see warning messages like “DNS SPOOFING DETECTED” or “REMOTE HOST IDENTIFICATION HAS CHANGED” do one of the following:
(a) Delete the “known_hosts” file in your “.ssh” folder in the home directory of the machine from which you are logging into the Discovery Cluster.

(b) If you do not want to do the above every time you see the warning message and want something more permanent then do the following:
– Delete the “known_hosts” file in your “.ssh” folder in the home directory of the machine from which you are logging into the Discovery Cluster.
– Login first to “discovery2.neu.edu” and logout. Then login to “discovery4.neu.edu” and log out.
– Now in your “known_hosts” file you will see two entries similar to what is as shown below:

discovery2.neu.edu,129.10.0.22 ssh-rsa m4KOOPWpxnTUqLdqAy7PCfG+FDZADOwNSaIkJ251CCv2IV6FI9i6FUFh/ZwYEivLmLFbXLacLwU4Cgv5fiEyAQISsqYyw==
discovery4.neu.edu,129.10.0.24 ssh-rsa /W4XdXCzJ1cmJQXa2qnzj3VaZ+87gM97EtdzGtZe3egDoEkoYACwUzdApCUiF8oivNjtRbEkqyYCElevPWfY6g+1dy6ow==

– Copy both and replace “discovery2.neu.edu,129.10.0.22 ssh-rsa” and “discovery4.neu.edu,129.10.0.24 ssh-rsa” with “discovery.neu.edu ssh-rsa”. Remove the ip address in each case. The file will now look like:

discovery2.neu.edu,129.10.0.22 ssh-rsa m4KOOPWpxnTUqLdqAy7PCfG+FDZADOwNSaIkJ251CCv2IV6FI9i6FUFh/ZwYEivLmLFbXLacLwU4Cgv5fiEyAQISsqYyw==
discovery4.neu.edu,129.10.0.24 ssh-rsa W4XdXCzJ1cmJQXa2qnzj3VaZ+87gM97EtdzGtZe3egDoEkoYACwUzdApCUiF8oivNjtRbEkqyYCElevPWfY6g+1dy6ow==
discovery.neu.edu ssh-rsa +m4KOOPWpxnTUqLdqAy7PCfG+FDZADOwNSaIkJ251CCv2IV6FI9i6FUFh/ZwYEivLmLFbXLacLwU4Cgv5fiEyAQISsqYyw==
discovery.neu.edu ssh-rsa W4XdXCzJ1cmJQXa2qnzj3VaZ+87gM97EtdzGtZe3egDoEkoYACwUzdApCUiF8oivNjtRbEkqyYCElevPWfY6g+1dy6ow==

– Save the “known_hosts” file. Now when you ssh using “discovery.neu.edu” you will never see the warning messages.

To transfer files and folders to and from the cluster use either “sFtp” or “rsync”. “rsync” is the preferred method as it uses secure encoding and can restart if connection is broken.

You can also use a free sFtp Windows or Linux Utility like FileZilla. A screen shot of what to enter is shown below. The port to use is 22. It can be downloaded from https://filezilla-project.org/ – ensure you get the “FileZilla Client” for install. For Host use “discovery.neu.edu”, for Username and Password use your myneu credentials. For port use “22″. Then click “Quickconnect”. If you get a warning check the box to update keys and proceed. Click image below for better resolution.

filezilla

Contact “researchcomputing@neu.edu” if you have questions or need help at any time.