Accessing the Cluster

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Caviness currently features two login nodes through which users interact with the cluster. The host name caviness.hpc.udel.edu will connect you to one of those two nodes¹⁾. For example, from a terminal window on a Mac or Linux client:

localhost$ ssh «username»@caviness.hpc.udel.edu
    :
[«username»@login01 ~]$

The default shell prompt on Caviness displays the name of the login node. If a user must connect to a specific login node, use that node's full domain name:

localhost$ ssh «username»@login00.caviness.hpc.udel.edu
    :
[«username»@login00 ~]$

When reporting connection problems, please include the -vvv flag in your ssh command to produce verbose output and include that output in your help ticket.

Do not run the ssh-keygen command on Caviness. This command can destroy your account's ability to login to compute nodes without requesting a password.

Alteration of your .bashrc and .bash_profile files is strongly discouraged. Adding directories to the PATH, LD_LIBRARY_PATH, and PYTHONPATH environment variables is best done using VALET packages and not by adding code to your .bashrc file. Keeping .bashrc and .bash_profile as close to pristine as possible often prevents difficult-to-debug problems from occurring when running jobs on the cluster.

The .bash_udit file in your home directory controls shell customizations offered by UD IT:

Variable	Description
`IT_WANT_ENV_EXTENSIONS`	Set to `yes` to enable the affects of the other variables
`IT_SET_WORKGROUP_ON_LOGIN`	Set to `yes` to automatically change to your default workgroup at login
`IT_DEFAULT_WORKGROUP`	The name of the workgroup to use by default; if unspecified, then the first workgroup listed by the `workgroup –query workgroups` command
`IT_WORKGROUP_CHDIR`	Change to the workgroup's `$WORKDIR` by default

For example, if the user edits .bash_udit to set:

IT_WANT_ENV_EXTENSIONS="yes"
IT_DEFAULT_WORKGROUP="«workgroup»"
IT_WORKGROUP_CHDIR="yes"
IT_SET_WORKGROUP_ON_LOGIN="no"

then the shell and workgroup command will behave as follows:

localhost$ ssh «username»@caviness.hpc.udel.edu
    :
[«username»@login01 ~]$ workgroup
WARNING:  Your working directory has been changed to /work/«workgroup»

[(«workgroup»:«username»)@login01 «workgroup»]$

¹⁾

Round-robin DNS load balancing returns multiple IP addresses when the name caviness.hpc.udel.edu is looked-up, in random order. Your SSH client will use the first IP address returned.

Accessing the Cluster

Shell customization