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Table of Contents
Getting Started with the Cluster
Cluster Login
Connecting via Browser
The cluster has recently been refreshed to Rocky Linux 9 (Enterprise Linux 9) and you can now fully access the nodes from your web browser. To do so:
Connect to the university VPN.
Once connected, go to one of the following addresses in your browser:
You will be greeted with a login screen. Please use your UMD username and password (the same you would use with CAS) to log in to the server.
If successful, you will now be at the cluster node's dashboard.
The Dashboard
The dashboard is a web-based interface that will allow you to do most anything you'll need to do with the node.
Overview Module
You'll typically start at the overview module, which will give you the following:
1: The navigation pane. This will allow you to move between different modules of the dashboard. You'll primarily use Overview, Navigator, and Terminal. The pane you select will be shown on the right side of the screen. This bar will persist between modules.
2: The server's message of the day (MOTD). This will be updated with any relevant notices or alerts.
3: The server's current utilization. You can see here if the server is being heavily utilized, so you can move to another, less-active node if needed.
4: The server's current hardware status. This shows the make and model of the current server, and how long it has been active without a restart.
Navigator Module
This module will allow you to securely upload and download files from the cluster. If you are unsure of what the buttons do, you can hover over them to gain a description of their function.
1: Navigation buttons (Back / Forward / Up / Refresh)
2: Address Bar (shows current directory, but you can input whichever directory you wish to go and hit ENTER)
3: Search in current directory
4: File Functions (Create Folder / Create File / Create Symlink / Upload File)
5: Folder window. Shows contents of current folder. You can use right click to perform file functions such as downloading and editing
6: Properties of currently selected item
7: Navigator Options (List or Grid view / Show hidden files / Dark or Light mode)
Terminal Module
This module provides an SSH connection to the current cluster.
1: The current user, node, and working directory.
2: The main terminal window, where you issue commands and read standard output.
3: Context (Right-click) menu in the terminal window. Allows for copy/paste and shows keyboard command equivalents (NOTE: The browser may need to ask if it can access clipboard content. Allow for this function to work.)
4: Terminal options (Font size / Background Color)
Using the Linux Shell
From the Linux prompt you can move your files around, check on your jobs, manage your disk space, and run programs. Below are some brief introductions to basic commands. For more info, this is a reasonably good tutorial. Note that most of the the Linux shell functionality is the same as a UNIX shell (the shell that you get when you open a Mac terminal). There are many resources online to help you learn how to use the Unix shell.
ls
The ls
command lists the files in a particular directory. To use it, type ls
at the prompt and press enter:
[username@econ1 ~ ]$ ls
You can use wildcards with ls
to list only files matching a particular expression. That is, the command
[username@econ1 ~ ]$ ls *.do
will list only your .do files in the current directory.
mv
The mv
command allows you to move files or directories from one directory to another
mv [file] [directory]
mkdir
The mkdir
command creates a new directory. It's usage is
mkdir [new directory name]
rm
The rm
command deletes the files specified after the command. The following code would delete all .do files in your current directory.
rm *.do
You can delete an entire non-empty directory with:
rm -r [directory]
rmdir
The command rmdir
deletes an empty directory:
rmdir [directory to delete]
man pages
To get help about a command, you can view it's “man page,” which describes how the command works. It describes the syntax and usage for the command. To view a man page, type:
man [command]
You can move up and down the man page with the arrows. Typing q quits.
Changing your Password
You can change your password by using the command:
passwd
at the command prompt. You will be prompted for your current password. Type this password and press enter. Note that when you type your password, no characters will appear. This is for security purposes and is normal.
Next you will be prompted to enter your new password twice. Do so, and your password will be successfully changed!
Creating an alias
Sometimes you use a certain command so many times that you just can't type it anymore. That's where the aliases come helpful. Just as the name suggests, you can tell the cluster to use some new (shorter) command in place of the one you use often. As an example, every time I log in to the cluster, I go to cd ~/files/pics/cute_pics/cats
and I want to change it to just cats
.
First, I start editing my bash profile with any text editor. For example
nano ~/.bash_profile
Then I go to the space below # User specific environment and startup programs
and type
alias cats="cd ~/files/pics/cute_pics/cats"
I save the file and refresh the changes by typing
source ~/.bash_profile
Now typing
cats
sends me directly to the folder I need.