PLEASE: in order to make sure that we can speak together giving the same meaning to the words used take one minute to read some definitions described below

Let us first agree about some concepts:

"server" : a machine which offer some service.

Depending of the kind of service offered we differentiate between many kinds of "server":

• "cpu server": a machine which offer its CPU to run programs.

Example: so called "number crunching" machines are the SUNs "sheliak", "betelgeuze", "procyon", and others

• "display server": a machine on which you 'see' on its monitor the graphic output of a program which runs on a "CPU server" (can be the same machine).
  Our "SunRay" machines are a good example of "display servers"
• "file server": a machine with harddisk(s) that can be 'exported' and usually mounted as NFS over the network. i.e. your data physically 'reside' on the harddisk of the "file server" but you are logged in (i.e. "working") on some other machine.
  On our file servers we usually use RAID 5 disk arrays.
  One of the file servers is for instance "spitfire".
  Users should NEVER run applications on a file server. Otherwise users are encouraged to run file intensive searchs or copy procedures ON THE FILE SERVER in order to avoid unnecessary transmission of data across the network.
• "mail server": is a machine which have the system 'mail folder' and send and receive mail from the outside world and redistribute it inside a "domain". Example: "smtp.ee.ethz.ch" is the 'mail server' for our institute.
  Our mail domain is "ifh.ee.ethz.ch"
• "www server": this machine runs a special program that gives access to WWW requests from the whole world. Example: "www.ifh.ee.ethz.ch" is the www server of our institute.
  Of course, this name "www.ifh.ee.ethz.ch" is an alias for a server, today (2005) this is "spitfire", a SUN server. On this server we run "apache".
• "printer server": is a machine on which a printer is physically connected. The spooler directory is also on this machine. Other machine send 'print jobs' to it.
• "NIS or NIS+ server": this machine has a data bank and gives the information to other machines when requested. There are one "master" and none, one or more "slave" or "replica" servers.

"job": a task to be executed

There are many different kinds of "jobs". I would like to define only two types: "local" and "remote".

• "local job": a task which will be executed on the "local" machine (see below).
• "remote job": a task which will executed on a "remote" machine (see below).
• "local" machine: is the machine whose keyboard, mouse and monitor you are now using. Often is the machine on your desk, sometime one machine out of a pool (as in K71).
• "remote" machine: all others   :-)

"user": a person who has a valid account on our net.

• "super user": the system manager. A trusted person who have access to all files (also system files) on a machine.
• "local user": one working on a 'local' machine. Also defined as the " owner" of the 'local' machine.
• "remote user": any user who is logged into a machine via net, i.e. is not using the keyboard, mouse and monitor of the machine.

"nice": a command used to let 'remote jobs' appear nice to the 'local' user .

Thank you very much for reading all this.

Ciao Ray

P.S. Please, mail suggestions (very welcome) to ballisti@ifh.ee.ethz.ch