Account are personal and login credentials must not be shared with others. If detected, access to the account will be automatically disabled. It is still possible and easy for multiple users to share and collaborate on the same folders and scripts. Don’t hesitate to ask if you don’t know how to do this - we’re here to help.
Access to C4 is only available from the UCSF network. If you are outside the UCSF network you must first connect via the UCSF VPN.
To access the C4 cluster you need an account - any UCSF Cancer Center member can get an account upon request. Anyone with a C4 account, can access the cluster via Secure Shell (SSH).
The instructions below requires:
An SSH client available on your local computer
A C4 account with valid authentication credentials
Users on Linux, macOS, and MS Windows have an SSH client built-in, which is available from the terminal as ssh. We will use that one in all our examples. You can also use other SSH clients if you prefer, include PuTTY on MS Windows. If you choose to use another SSH client, consult that program’s documentation for further instructions. Another alternative, which some might find easier, is to connect to the cluster using the X2Go software.
To log into the cluster, assuming your user name on C4 is alice (case sensitive), do the following:
Make sure you are on the UCSF network or the UCSF VPN
open a terminal (‘Terminal’ on macOS and most Linux distributions, and ‘Windows Console’ [old] or ‘Windows Terminal’ [modern] on MS Windows),
At the terminal prompt, type ssh alice@c4-log1.ucsf.edu and press ENTER
When prompted, enter your C4 password and press ENTER
The C4 cluster has two login servers, (i) c4-log1.ucsf.edu and (ii) c4-log2.ucsf.edu. Feel free to use either.
When logging in from your local computer while on the UCSF VPN, you should see something like:
{local}$ ssh alice@c4-log1.ucsf.edu
alice1@c4-log1:s password: XXXXXXXXXXXXXXXXXXX
[alice@c4-log1 ~]$
If you get Permission denied, please try again. when you enter your password, make sure you use the correct C4 username (case sensitive) and the correct password.
It is possible to set up password-less authentication via a public-private SSH key pair. For details, see the how-to page Log in without Password.
The login node is dedicated solely to very basic tasks such as copying and moving files on the shared file system, submitting jobs, and checking the status on existing jobs. Note that most software tools are not available on the login node, which means you can neither use it for prototyping scripts nor build software. Instead, for such tasks, use a development node, which is configured identically to the compute nodes.
Like for all Unix-based system, to log out from C4, type exit or logout (standard Unix commands) and press ENTER. For example,
[alice@c4-log1 ~]$ exit
Connection to c4-log1.ucsf.edu closed.
{local}$
An alternative is to press Ctrl-D (sends “End-Of-File” [EOF]) at the command-line prompt.
Any shell session that has been idle for more than 24 hours will timeout and exit automatically.