Brandeis Computer Science Department
Systems Usage Policy

Revision 1.10

Current version of the usage policy is at

Department Resources

All computer science students have access to Unix (Linux and Macintosh) Workstations. Unless you have explicit permission, you may only use one of the public machines. should only be logged into in order to change your password (passwd), shell (chsh), or finger information (chfn).

Graduate students may also have access to other machines, depending on their needs and advisor.

There may, at times, be more people who want to use machines in the Berry Patch (Volen 119) than there are available machines. Therefore, there is a hierarchy of which tasks take precedence over others. Classwork, research, and related activities have the highest priority.

The machines can be reached via ssh.


Games should never be played on the workstations between 9AM and 9PM. After hours, if the lab isn't full, and you want to play a game, it's OK to do so. Be aware, however, the multiplayer games can take up a significant portion of the network bandwidth. When choosing a machine to play on, look at the loads on the various machines and chose the machine with the lowest load. As another bandwidth concern, never run the game on one machine and have it display on another.

If more than two-thirds of the workstations in room 119 are in use, anyone playing a game on a workstation should stop, so that if someone comes in to do work they can do so.

There may be periods of time (such as exams and at the end of the semester) when graphical games may be totally prohibited because the systems will be needed for people to do course related work.

Disk Usage

Undergraduates have a 30 megabyte disk quota. There is no problem using significantly more space for a day or so if you are using your account as a 'staging area' for a large file transfer. Obviously you may not use the Cosci systems to pirate software or for other illegal purposes. Having pirated software or music on your account is grounds for account revocation and legal action, where appropriate.

Graduate students are not on a specific quota, but are asked to keep their disk usage reasonable.

You can check your disk usage with the command sequence:
cd ; du -sk
The number this returns should be under 30,000 for undergrads. Any user who is over quota is subject to having his or her files deleted to bring the disk usage down. Files deleted because a user was over quota will not be restored. Any user who is habitually over quota is subject to having his or her account terminated.


Your account is a privilege given to you so that you may learn about the UNIX operating system and do your Computer Science homework. Under no circumstance should you ever give out your password or allow anyone else to use your account.

If you think someone has your password, change it immediately. When choosing a password, do not use any part of your name, either forward or backwards. Also, don't just use a normal word with a number or special symbol tacked on the end. The characters @ and # should generally not be used in a password because they can be misinterpreted by the login procedure.

You change your password by logging into the machine named and typing the command "passwd". This is the only reason you should be logged into, and you should log out immediately afterwards. The password will be changed within 2 hours.

If someone other than you is found using your account, the account will be turned off until you speak with the System Administrator in person. If this happens more than once, the account will not be turned back on. There will be no exceptions to this policy. If you need this account to do your homework, protect it accordingly.

Common Courtesy

Be courteous to your fellow users. Keep your voice down while you are in the Berry Patch. Do not leave trash lying around in the Berry Patch. Do not do anything that would be disruptive to other people trying to work. In addition, if you see someone who needs a workstation and you are doing something low priority (like playing a game), don't wait for them to ask you to move. Log out and get up by yourself.

We now allow food in the patch. Please be sure to keep your space clean.

If you are going to walk away from your terminal, be sure to use a screensaver that requires a password. Note, however, that you should never leave a terminal locked for more than 30 minutes. If you are going to be gone longer than that, log out instead of using a locked screensaver. You may be logged out automatically if you are idle for more than 30 minutes. Never ever leave the machine unless you are logged out or have your session locked. Never ever leave 119 unless you are logged out or have your session locked. You should also log out if you will be away from a remote login for more than a few moments, as this is a security risk. You should have the autologout environment variable set to the value 60 or smaller, for this reason.

If you have a question about whether what you want to do is permissible, please ask guru before trying it.


Each user will be limited to 400 pages of laser output per semester. We will be keeping track of the amount of pages printed by each user to this printer. In addition, we ask that you be courteous and NOT print all 400 pages in one day. This inconveniences everyone else using the printer, since, despite its super-hightechiness, the printer will still periodically run out of paper and will not get refilled untill the next business day. So don't be a paper-hog.

System Administration

The Systems Administrator is Christopher Page (cpage at cs dot brandeis dot edu). His office is Volen 125b, and his extension is x62717. However, if you have a problem or need assistance, you should try a guru (see below) before you see Mr. Page.

The gurus are students who are employed by the department to help administer the systems and answer user questions. The guru office, is Volen 125a, and the phone extension is x62740. Generally, there is a guru on duty from 9AM till 5PM every weekday. You can also mail to guru at cs dot brandeis dot edu, or talk at guru if the guru account is logged on. Feel free to stop in...

There is a list of frequently asked questions at, which all users should read.

There is also a nice list of Unix resources (for help in general, or learning) off of guru's home page,, which you should view if you are curious.

If Mr. Page is not around, a guru is fully authorized to act in his place if a problem or question arises.

An up to date listing of all current gurus is maintained on guru's homepage.

One final word on the gurus. The gurus are students and frequently have work they need to do, so if they are logged in as themselves, and not as guru, please don't talk at them unless it really is urgent. Do NOT, under any circumstances short of system failure, call them at home.

Other Miscellaneous Stuff...

If you need to run long, processor intensive applications on the department machines, do not run more than one on any given machine, and never more than 3 total. If you anticipate needing to run long programs more than once or twice a semester, please talk to a System Administrator in advance. We have special machines for such projects, and are happy to support academic research. (It's why we're here!)

New Programs. We're generally willing to install non-beta versions of new programs if they are needed. Just mail to guru with the information, and we'll try to get it running if there is a demand for it.

Backups. Backups of the system are performed at least once a week. However, don't come to rely on them. Be careful of what you delete because backups are guaranteed to fail when you need them most.

SPAM SPAM and chain letters are prohibited. They are generally considered to be rude, and are definitely a waste of network bandwidth. Please do NOT propagate them. Craig Shergold is alive and well, and has already made a world record. Dave Rhodes is in jail for mail fraud. Virus alerts are often themselves a clever form of sematic attack.

File Permissions. Be aware that the default permissions for newly created unix files and directories are 644 and 755, respectively. This means that anyone on the system can read files that you create unless you take steps to protect them, such as creating private subdirectories for your work and using chmod to change the file permissions.

System Cracking. Anyone caught trying to crack any system, ours or elsewhere, from one of the Department's machines will have action taken against them, including closing the account, and possible referral to University or legal authorities. Especially after 09/11/2001, the FBI takes a dim view of such activity.

Illegal File Sharing. Anyone caught offering or having software for distribution where it is illegal to do so will have their account revoked and possible referral to University or legal authorities. This includes, but is not limited to, illegal distribution or allowing downloads of MP3's, private software, copyrighted material, and personal homeworks. Copyrighted material may be deleted at the whim of the System Administrator.

Laptops. There are at least four open ports in the lounge (Volen 118, next to the patch). They are labelled and laptops can be plugged in to them. Set your computer up to acquire an address via DHCP. Anyone caught unplugging patch workstations to plug in a laptop will lose access to the patch pending a hearing by the J-board.

Violations of these policies may result in referral to the Office of Campus Life under section 1 of "Rights and Responsibilities".

This policy is subject to change at any time. All changes will be posted to guru's website.

Any other questions should be addressed to a guru or to Mr. Page.

last modified 04 September, 2007.