Logging In

Setup

Ensure that you are enrolled in Penn’s Two-Step Verification System. If you are familiar with Duo for other Penn systems, you are likely already enrolled.

You *must* be on Penn’s campus or on the Penn GlobalProtect VPN

For the Betty supercomputer, we use a two-of-three factor authentication system to keep accounts secure while allowing flexibility for users. You must successfully complete any two of the following methods before you can log in:

Kerberos (kinit) – Uses your PennKey and password to verify your identity.
SSH key – Verifies you are logging in from a trusted device with a registered public/private key pair.
Duo – Adds an extra layer of security with a mobile push notification, text message, or hardware token.

Ubuntu

Install the required packages for Kerberos in your Ubuntu environment.

sudo apt update
DEBIAN_FRONTEND=noninteractive sudo apt install -y krb5-user

mkdir -p $HOME/.ssh
echo """
Host *.upenn.edu
    VerifyHostKeyDNS yes
    GSSAPIAuthentication yes
""" >> ~/.ssh/config

MacOS

Your Kerberos packages are already installed. You just need to setup ssh to enable GSSAPI on the Betty system.

mkdir -p $HOME/.ssh
echo """
Host *.upenn.edu
    VerifyHostKeyDNS yes
    GSSAPIAuthentication yes
""" >> ~/.ssh/config

Windows

Please install WSL2.0 to install Ubuntu as a Windows native environment. Please see the Microsoft instructions here.

Grab a ticket from Kerberos to login. You will need to request a new ticket every 10 hours. Please follow the Duo prompts that follow. Please remember to use UPPERCASE UPENN.EDU – otherwise it will not work.

kinit <PennKey>@UPENN.EDU
ssh <PennKey>@login.betty.parcc.upenn.edu

Congratulations! You should now be logged into Betty!

If you intend to use tmux or similar persistent sessions, please make note of which login node you actually got to. Here is a quick list of their hostnames.

login01.betty.parcc.upenn.edu
login02.betty.parcc.upenn.edu
login03.betty.parcc.upenn.edu

✅✅✅ Tips

Conda environments on your local system must be deactivated before kinit can work.

conda deactivate
kinit <PennKey>@UPENN.EDU
ssh <PennKey>@login.betty.parcc.upenn.edu

If you are running into issues with kerberos:

Kerberos debugging document
Reach out to PARCC

SSH Key

To simplify your login experience we recommend setting up an ssh key to use. If you do not already have one, generate one from you local laptop or workstation with the following command.

ssh-keygen -t ed25519

Once this is generated, you can share it with Betty to use for your next login.

kinit <PennKey>@UPENN.EDU
ssh-copy-id <PennKey>@login.betty.parcc.upenn.edu

SSH Multiplexing

Users can take advantage of multiplexing to avoid having to authenticate (entering userid and password) every time one opens an ssh connection or use scp, one can sign up once and use the same connection to open new windows on Betty.

On your local laptop/workstation enter the following text into a file (create it if necessary):

echo """
Host *.parcc.upenn.edu
    ControlMaster auto
    ControlPath ~/.ssh/control:%h:%p:%r
    VerifyHostKeyDNS yes
    GSSAPIAuthentication yes
""" >> ~/.ssh/config

Then, start the main connection, for example:

ssh -fNM <PennKey>@login.betty.parcc.upenn.edu

Now, in a new window, when you login to Betty, you will no longer need to provide another authentication:

ssh <PennKey>@login.betty.parcc.upenn.edu

The only downside is that simultaneously transferring large files and trying to work on a terminal through the same connection may cause lag in your terminal.

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