University of Minnesota
Computer Science & Engineering Help Pages
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User Security

  • Do not share your account or password

    Your username identifies you to the CS&E, CSE and University communities, and to the Internet community as a whole. You are solely responsible for how your account is used, regardless of whether or not you have given another person permission to use your account.

    If someone needs access to CSE resources, even on a temporary basis, then that person should contact Systems Staff and arrange for his/her own account.

    If someone else offers you use of an account for which you do not have authorization, decline. Also, if you discover someone else's password, do not use it. In either case, you should report the event to the Systems Staff operator.

  • Make a good password and keep it secure.

    Anyone who knows your password can use your account.

    1. Change your password often.
    2. Avoid writing it down where someone else can find it. Remember, if you lose the piece of paper that you wrote your password on, you need to change the password immediately.
    3. Do not use the same password for multiple accounts. Your account is only as secure as the least secure account it shares a password with. Many web and chat accounts do not use high encryption for their passwords, or send the password to the user in plain text emails.
    4. Do not send your password over email. Email is plain text, and completely insecure. System Staff will never ask you for your password via e-mail, IRC, or any other form of online communication. If someone claiming to be a sysadmin asks for your password via an online method, be immediately suspicious and notify the Systems Staff Operator as soon as possible.
  • Lock your workstation when you leave the lab.

    If you leave your workstation unattended and unlocked while you are logged in, anyone who sits down at the keyboard can use your account. Locking the workstation allows you to enter your password to unlock it when you return. Do not leave the workstation locked and unattended for more than 15 minutes. You may return to find yourself logged out.

    UNIX: Use the "xlock" command at the prompt (type "man xlock" for more information).
    Windows: Press the "ctrl" "alt" and "del" buttons together, and select the "lock workstation" option.

  • Do not circumvent, or attempt to circumvent, system security settings.

    Use of your account to subvert or change the system endangers the security of the entire network. Any attempt will be interpreted as a hostile action and your account will be closed. Reactivation of your account may require that you explain your actions to the Associate Dean of Student Affairs and/or an ITICC member. This wastes everyone's time and creates hard feelings; don't do it.

  • Report any problems or unusual behavior to the Systems Staff Operator.

    The sooner a problem is known about, the sooner it can be fixed.

  • Check your account for signs of unauthorized use (theft of service).

    Some indications include files you didn't create, directories with unusual names (like " "), wildcard entries in your ~/.rhosts file, and last login times you don't recognize.

Systems Staff is available to answer questions and address problems.

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Peer to Peer (P2P) Software

Peer-to-peer software is generally considered unacceptable to use on the University network except in rare situations. We ask that users refrain from using peer-to-peer software in the workplace.

If the usage is both legal and directly related to their work, users may request special permission from the Systems Operator. Please specify time(s) and machine(s) for the requested P2P software usage.

Long Term Processes

Nice the Process

If you run a job that requires a lot of CPU time, you should nice the process. The "nice" command is used to start a process with different priority. So any job that will take a long time to run should be run as:

nice -n nice_value command arguments

where nice_value is a number from 1-19 (larger value → lower priority), command is the command you want to run, and arguments are the arguments you pass to nice.

For more information about nice see the manual pages on nice (man nice).

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CS&E Users

Machines Available

There are two groups of machines:

  • publicly accessible machines (servers for general users, Grad Lab machines, etc...)
  • research machines (owned by specific research groups)

General users should use the publicly accessible machines to run long term processes.

The computer servers available for this purpose are:

  1. julius.cs.umn.edu - Sun Fire V440 with 8GB memory and 4 processors
  2. dio.cs.umn.edu - Dell Poweredge 6950 with 14GB memory and 8 processors

A list of machines available for remote access can also be found on the CS&E Instructional Computing Resources page.

Steps to follow

If you are using the Grad Lab machines to run long term processes then you should do the following:

  1. nice the process
  2. Send an e-mail to operator [at] cs.umn.edu with:
    • Process id’s
    • What machine they are on
    • What project they are for
    • Expected end date

Attention Grad Lab users: Please do NOT reboot the machines just because you think they are slow. This can interrupt other peoples’ processes running on those machines and it could also corrupt the file systems on the machines badly enough that will require reinstalling the machines, which helps no one.

If you feel a system is slow, send an e-mail to operator [at] cs.umn.edu or call 612-625-0876 to report the problem. The Systems Staff can determine if there is a problem and help to resolve it. There are very few problems that require a reboot.

CSE Labs Use

CSE Labs machines are to be used primarily for instructional purposes, but they can be used for research purposes if your advisor obtains permission from Professor Paul Strykowski (pstry [at] umn [dot] edu), Associate Dean for student affairs. Your processes should not interrupt normal class activities.

There are some computer servers available for running long term processes. They are:

  1. zeus.cselabs.umn.edu - Sun T1000 with 8GB memory and 6 cores (with 4 threads/core, which makes it look like 24CPUs)
  2. apollo.cselabs.umn.edu - Dell Poweredge 1430 with 8 cores

There is also an 8 machine ‘candy bar cluster’ in CSE Labs consisting of 8 SunFire V210s with 2GB of memory and 2 processors each. They are:

  1. almondjoy.cselabs.umn.edu
  2. crunch.cselabs.umn.edu
  3. heath.cselabs.umn.edu
  4. kitkat.cselabs.umn.edu
  5. milkyway.cselabs.umn.edu
  6. mounds.cselabs.umn.edu
  7. snickers.cselabs.umn.edu
  8. twix.cselabs.umn.edu

A list of machines available for remote access can also be found at CSE Machine Listing.

There has been mention of the 'itclus' machines in CSE Labs. These machines are for specialized class purposes only and not for running long term processes. These machines are being used for a particular class this semester and we will limit access to them if we have to. Do NOT run any processes on these machines unless you are in the class that is using these machines.

If you want to run processes for a class that would take long time, you should do the following:

  1. nice the process
  2. Send an e-mail to operator [at] cs.umn.edu with:
    • Process id’s
    • What machine they are on
    • What project they are for
    • Expected end date

Acceptable Use Policies

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Contact: 1-213 Keller Hall, 200 Union St SE, Minneapolis, MN 55455   Phone: (612) 625-0876   Email: operator@cs.umn.edu