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Computing FAQ

Computing FAQ


General Issues

Certificate Authority public key The Department of Computer Science has its own Certificate Authority for use with secure connections. This will be used to authenticate the certificates used to secure https connections (such as webmail) as well as secure connections with POP and IMAP.

Account issues

What is my quota limit?

1GB is the default quota limit.

How can I tell how much disk space I am using?

You can use the `myspace` command to report your disk utilization and your quota allocation.

My class requires more space than I have available. How can I get my quota increased?

Talk to your Professor about your quota needs. They will request a quota increase from the System Administrators

Okay, I am in my account, and it is over quota. What do I do?

You can run findhog to see what the 20 largest files in your home directory are. Alternatively, findhog x will find the largest x files in your home directory
There is also a script called rm-junk that goes through your home directory and looks for caches and core files and asks you if you want to remove them. Just type "y" at the prompt and it will delete them for you.

I have changed some of my dot files, and now I have problems with my account.

You can get a copy of the default dot files (.bash_profile, .cshrc, .login, etc.) from /usr/local/pub/X/

Can I change my shell?

Currently you can not change your own shell, but if you want your default shell changed from bash you can contact the System Administrators (70-3590) and they can change it for you.

How do I change my password?

You can change your password with the command cspasswd. This is available on any DCS linux machine.  A reference document about good password practice is found in the HOWTOs section of this Web site.

My unix password does not work on the Windows machines. What do I do?

Your passwords are out of sync. You will need to see the System Administrators in room 70-3590 to get your passwords re-synced

When I run the cspasswd command it complains that it can not change my NT password. What gives?

Your passwords are out of sync. You will need to see the System Administrators in room 70-3590 to get your passwords re-synced

Help! I deleted some important files in my account! How do I get them back?

If the files existed overnight, they can be backed up from that point in time. Send mail to with the file name(s), the last time it was modified, and where the files existed in your directory.

I have a project that will take several hours of compute time, but I don't want to sit around and wait for it -- what can I do?

The best way to do this is to no-hup the process (see the nohup man page) so it continues to run after you log out, and nice the process (see the nice man page) up to 20.

Can I connect to the CS machines remotely?

You can use ssh to connect to any of the linux machines in the lab. Available tools for remote connection to the lab machines.  See the HOWTOs section for instructions on using these tools.

    Shell Connection:
  • SSH
  • Putty
    GUI Connection
  • xming
  • X11

Can I remotely run programs that require a GUI interface?

Yes you can. Please see the series of HOWTOs for various client operating systems.

How do I copy files from my own machine to my CS account?

You can use a USB flash drive.
You can use various tools to securely connect to the CS lab machines. See the HOWTOs section for instructions on using these tools.

  • SFTP
  • SCP

Does the CS Department provide FTP access?

ftp-like access is available through sftp on any of the lab machines.

Software and Configuration

Firefox won't start.

First make sure you're not already logged into another CS computer. You can only run Firefox on a single machine at a time.
If that's not the issue, then you will need to manually remove the lock file for the browser. We have a script called fixfox that you can run. It will remove the lock files for you. When Firefox or Chromium crash, they will leave these files in your account which will keep you from opening them on any CS computer. The files you need to remove are:

where ???????? are random numbers and letters unique to your account (i.e. wed4pa82)


The Department of Computer Science provides mail for students taking CS courses. Many faculty and advisor messages will be sent to your CS account, and it i s assumed you are reading it.

Your mail address is

As of Fall 2017, student accounts will by default have their mail forwarded to

What mail services are available for my Computer Science Account?

We provide webmail access, secure POP3, and secure IMAP.
Some basic configuration information:

  • pop/imap mail server:
  • imaps (secure) port: 993 (use SSL)
  • pop3s (secure) port: 995 (use SSL)
  • outgoing smtp port: 587 (use TLS)

Where do I get information on how to connect with my favorite mail client?

There is info on mail client connections in the HOWTOs section for this site.

Can I forward my email to another system?

By default new student accounts already forward to This can be removed by commenting out the forward in your .procmailrc file. (please see HOWTOs section)

If you want to forward your mail, there are a few options. The preferred method is to modify your .procmailrc file(please see HOWTOs section). Another option would be To be able to forward your email to another account, you need the .qmail file in your home directory. The .qmail file should have & followed by the email address to which you are forwarding.The .qmail file should have the permission 600 otherwise the mail server will just ignore it.

Is mail filtered for spam and viruses?

Yes. Messages that contain viruses are quarantined. All other messages are ranked based on spam probability and an X-Spam-Status is added to your message headers. We will not filter it out for you.

Can I do any mail filtering?

Procmail is provided for mail filtering. In combination with Spam Assassin it makes an effective spam trap.  A good reference to doing this properly can be found in the HOWTOs section

Window Managers

What is the default window manager on the CS systems?

The default window manager is Gnome .

What other window managers are available?

How do I set up my window manager to be something other than Gnome?

There is a series of HowTos for using window managers in the HOWTOs section for this site.


What is contained in the Computer Science Department Code of Conduct?

Here are the security requirements for devices connecting to RIT's network.