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Accessing a cluster
This section uses the wiki's documentation conventions.
Secure shell program (SSH)
Use a secure shell program/client (SSH) to connect to the cluster and a secure file transfer program to move files to and from the cluster.
There are many suitable secure clients for Windows, Mac OS X, and UNIX/Linux. We recommend PuTTY and Xming for Windows users. Macintosh and UNIX/Linux users can use their pre-installed SSH and X11 software. (Newer versions of Mac OS X may not have a current version of X11 installed. See the Apple web site for X11 installation instructions.)
.ssh
directory. Do not manually erase or
modify the files that were initially created by the system. They facilitate communication between
the login (head) node and the compute nodes. Only use standard ssh commands to add keys to the
files in the .ssh
directory.
Logging on the cluster
To initiate an SSH connection from a Mac/UNIX/Linux system to the cluster's login (head) node, use the generic command
ssh
«options» «HPC_username»@«HPC_hostname»
For example,
ssh -Y traine@farber.hpc.udel.edu
This ssh command is on your local system. This example assumes you have a local command line interface, and have an X11 server running, for example, Mac/UNIX/Linux or cygwin/X (with the openssh client)
Screen sessions
When an ssh session is ended intentionally or by a loss of connectivity, you cannot generally restart it and resume your work. The UNIX screen command provides a useful solution. This command creates a virtual terminal window session that continues to run after you are logged off. It allows you to reattach the same virtual terminal window session and resume working. See the man page for screen for details.