Discouraged Practices

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The following practices are strongly discouraged on CISE computers and computing facilities. Under some conditions, they are appropriate, but anyone needing to engage in any of these practices should coordinate this with the CISE system staff in order to minimize the impact on departmental resources. Users who engage in these practices without coordinating with system staff may be subject to:

  • removal of offending processes without notice
  • temporary suspension of account privileges

Discouraged practices include:

  • Excessive CPU usage. Anyone needing to run jobs which require large amounts of CPU time should run the job in the following fashion:
    • Run only on a recommended CPU server (rain, sand, storm, thunder,...).
    • Run no more than 2 of these at a time.
    • Run them at a niceness level of 19 (see nice and renice man pages for details).
Running large CPU jobs under other conditions will be treated as a discouraged process. Such jobs may be killed without notice.
  • Excessive "temp" space usage. Using large amounts of standard "temp" space (including /tmp, /var/tmp, or /cise/tmp) can cause other programs which rely on this space to stop working. User's treating these "temp" spaces as permanent storage, or using them inappropriately are subject to removal of their files without notice.
  • Excessive network traffic. Processes requiring large amounts of network bandwidth must be coordinated with the system staff since they otherwise affect the performance of all machines on that network. Running such processes without coordinating with the staff is discouraged.
  • Monopolizing primary CISE machines. Some public machines play specially important roles (rain and sand for example). Anyone monopolizing these machines is subject to removal of files and/or processes in order to free up the machine.
  • Monopolizing public machines. The lab machines are for public use. CISE uses should not log in to these machines to access additional cycles at any time while the lab is open. Also, users are not allowed to log in to these computers, lock the screen, and then leave.
  • Spawning "fork bombs". As students of computer science, many homework projects require spawning subprocesses. These projects must be carefully monitored to make sure they do not spawn subprocesses out of control. Users allowing "fork bombs" to monopolize a CISE machine may be subject to suspension of login privileges on affected machines.
  • Monopolizing printers. Printing large numbers of files, or printing very long documents during the day when other people need access to public printers is discouraged. Offending print jobs may be removed. In this case, the user will still be responsible for any charges for pages printed.