Xunil Linux Servers♯

The Xunil machines are provided for ECE faculty and students for classwork requiring a Linux environment, Drexel or COE licensed software, or a CUDA environment. These systems are managed by CTS.

Every user is expected to adhere to the following policies when accessing Xunil:

Violations

Any violation of these policies will result in immediate termination of Xunil access, as well as possible further acadecmic disciplinary action.

No Research Usage Allowed

The software installed on the Xunil servers is licensed for teaching and classroom purposes only. Any user doing research using these machines will lose their access and any research data will be erased. Please consult with other members of your research group to see if your group already has access to a Linux server. If your research group would like to set up a new Linux environment, please contact us and we will be happy to assist.

What machines are part of the Xunil system?♯

Currently, the two Xunil hosts are:

xunil-03.coe.drexel.edu
xunil-05.coe.drexel.edu

What is my username and password for the Xunil Systems?♯

Every authorized user logs into Xunil with their drexel.edu domain account (e.g. abc123) and associated password.

How do I access Xunil off campus?♯

Xunil access is restricted to Drexel IP addresses. To access the system from off-campus, you will first need to connect to the Drexel VPN.

X2Go for remote GUI access♯

X2Go server has been installed on the Xunil hosts to allow for remote GUI session access. Traditional X11 forwarding over SSH works well in low latency situations, but over VPN, the responsiveness of GUI applications has been a major issue. If you need to access software on Xunil hosts that requires a GUI, then you are encouraged to install the X2Go client on your computer. Please choose Xfce as the session type when configuring the connection.

How do I access the Xunil machines from Windows?♯

The Xunil machines need to be accessed using an SSH client. On Windows PCs, we recommend the MobaXterm client. This allows you to SSH into the hosts, and provides a built-in SFTP client as well as a built-in X server for X11 forwarding GUI programs. If you're primarily running GUI applications, then using X2Go will give better performance.

How do I access the Xunil machines from a Mac?♯

The Xunil machines can be accessed using an SSH client. macOS has a built in terminal with an SSH client. This is located at /Applications/Utilities/Terminal.app on your system. If you're primarily running GUI applications, then using X2Go will give better performance.

How do I access the Xunil machines from a Linux machine?♯

The Xunil machines can be accessed using an SSH client. Almost all Linux machines come pre-installed with the necessary software for both text based and graphical X client connections. If you're primarily running GUI applications, then using X2Go will give better performance.

How do I verify I am connecting to the Xunil machines?♯

You can verify you are connecting to the proper servers by ensuring that when connecting via SSH the keys presented match one the fingerprints listed below:

Xunil-03 SSH Host Key Fingerprints♯

RSA4096: SHA256:5kV51qhPB0rzR0w8wekiYfhWh+BZTSjDviVqpZ56cfQ
ED25519: SHA256:9QBsMqXJSQ9rQszlUMPAb845JlDzPpmGuVKGyln5Ues

Xunil-05 SSH Host Key Fingerprints♯

RSA4096: SHA256:GExO8j1MykoBCcrY82ZMygtttoScmRfoih64dQXWjEk
ED25519: SHA256:9QBsMqXJSQ9rQszlUMPAb845JlDzPpmGuVKGyln5Ues

Where is my data stored?♯

Your data is stored in your home directory, located at /home/abc123@drexel.edu where abc123 is your DrexelOne username. These home directories are shared between both systems.

How long are the home directories stored?♯

We store the data in your home directory for the full academic year (September through August). The week before the start of the new fall term (in September) the home directories are cleared out and the data is erased. If you deem the data to be critical, you will need to backup your files off the system to personal storage.

Where is the licensed software located?♯

All licensed software is located in /opt.

I need to use the GPU for CUDA purposes, which machine has this equipment?♯

The GPU and all related CUDA software is on the xunil-05.coe.drexel.edu machine.

What happens to my SSH session if it’s logged in and idle?♯

All Xunil machines have a session timeout period of 12 hours. Any idle session going longer than this will automatically be ended. If you require more time, please use a terminal multiplexer. Tmux, Screen, and Byobu are all installed on the Xunil machines for this purpose.

What happens to my process if it’s affecting other users, taking up too many system resources, or running for too long?♯

Any process taking up significant processor and memory usage or running for more than 24 hours will be forcibly ended so that other users are not affected.

If I experience any problems, how do I get help?♯

If you experience any problems with the Xunil systems, please contact us. Include your username, what you were trying to do, what program you were using, and any error messages you received.