Computing Resources - anjavdl/PHY517_AST443 GitHub Wiki

Data analysis sessions and tutorials will take place in the Astro Computing Lab in ESS. You will receive an envelope with your username and password to these computers at the beginning of the course. Three of these computers have special roles: uhura and vulcan are the two (relatively powerful) machines on which all the astronomy software is installed - these are the computers on which you are encouraged to run your data analysis scripts, especially those working on the raw image files. kirk is the central server. Note that none of these three is physically accessible. All the other machines (spock, etc.) are mainly there to let you log onto uhura / vulcan / kirk remotely; but you can choose to use your own laptop to do so instead (see instructions below). There are enough computers so that every group can use one, but not enough for all students, so please bring your laptop if you have one.

The computers in the Astro Computing Lab all run Linux, with which you should be familiar from PHY 277. If you are a bit rusty on your Linux command line skills, you may find a "cheat sheet" such as this one useful.

You will receive either an e-mail, or a sheet of paper with your username and initial password. Do not give this paper to anybody else, or leave it lying around. With this account, you can log into any computer in the computing lab, directly or remotely (remote access is describe below). Your first action should be to change your password (see below).

The fastest (and recommended) desktop manager on our systems is MATE. To select it, click on the settings wheel on the screen where you enter your password. Please make sure to log out when you are done! Do not just leave the computer with the screen locked.
Do not restart the computer!

The first time that you log into a specific machine in the lab (e.g. spock), it will set up basic configuration files in your account's home directory on that machine, /home/<username>. This will make subsequent log-ins to the same machine faster. Everything else in /home/username will be deleted every night. To not lose your files, keep them on /kirk/home/<username> or /astrolab/Fall_22/<username> (both of these are visible from all machines).

The first time that you log in, you should change your password. To do so, log into kirk by typing the following into a terminal:

ssh [email protected]

replacing username with your personal username. Use the passwd command. Make sure to select a complex password and to keep it password safe! Our computers are under constant attack from outside - please do not make the system vulnerable.

The two most powerful machines in the Astro Computing Lab, uhura and vulcan, have been set up with all of the required software. You can work on them by logging in remotely, e.g. from one of the other computers in the lab, or your own laptop (see below).

We have a large disk to contain your data, which is separate from your home directory. The disk space allocated to is mounted under

/astrolab/Fall_22/username

where again you have to replace username with your personal username.

Also make sure to back-up your data, and your scripts(!), somewhere else, e.g. your google drive!

You can use your own laptop to remotely access (via ssh) the computers in the lab (you will want to log into uhura or vulcan directly), or one of the computers in the lab to log onto uhura / vulcan / kirk, etc. The instructions depend somewhat on your operating system (the computers in the lab all run Linux):

To log in with window formatting, type:

ssh [email protected] -X

The "-X" should allow window formatting. To test this, open a ds9 window:

ds9 &

If this does not work, try "-Y" instead of "-X".

Mac is also X-based, but needs to have X11 (the window system that Linux uses) installed. In newer Mac OS versions, you need to install this yourself by installing XQuartz. In XQuartz you can open a Terminal (in the Applications menu), from which you can use the same commands as described above for Linux systems.

See below.

You can use your own laptop to log into uhura and vulcan, see above. In addition, all of the software required for class is freely available. If you are running Linux or Mac OS X, you should be able to install it on your own laptop / computer. For Windows, see below.

To setup an SSH connection from a Windows machine, do the following:

• Download and install PuTTY: click on "putty.exe" here
• Download and install Xming: here
• Launch Xming and open PuTTY. Under "host" type uhura.astro.sunysb.edu. Under "Category:" on the left hand side, click the "+" sign next to SSH. Then under X11, click the box next to "enable X11 forwarding"
• go back to "Session," type a session name under "Saved Sessions" and click "Save."
• click "Open" at the bottom of the screen to start your session. Enter your username and password as directed.
• check that everything is working by typing ds9 into the command line. A new window should appear.

Once your session information is saved in PuTTY, you can login using the following steps:

• Launch Xming and PuTTY
• in PuTTY, click on the name of your saved session and then "Load"
• Click "Open" and enter your username and password

The cleanest solution is to partition your hard drive and install Linux in parallel with Windows. Alternatively, you can try an emulator:

Lately, we have had most success with VirtualBox.

CosmoBox comes with python and LaTeX pre-installed and allows you to work data files without loading them into the virtual environment; they get stored on your local machine. To install, follow the bullet points under "CosmoBox Desktop." Once you get CosmoBox running, you can refer to the Linux guidelines above!