Introduction
************

The PPPL Unix Cluster is a collection of Unix computers available for general use.  This document gives some basic information on how to use the Unix Cluster.

The computers discussed in this document are paid for by the taxpayer, used by many people, and connected to the Internet.  Since these computers are used in research, relatively few restrictions are placed on the way you use these computers. Thus, as a user of these computers you have certain obligations:

  * Make sure you pick a good password (see Choosing and Setting Passwords).   We need to be sure that only authorized users gain access to the computers.  Passwords are the main line of defense against computer abuse.  A password that is too short or is a common word can be guessed by malicious outsiders.

  * Please be judicious in your use of the computers.  It's easy, for example, to overwhelm the network, fill up the disks, etc.  If someone notices you doing this, you may be asked to modify your behavior.  We'll try to find other ways for you to accomplish your work efficiently.

Goals
=====

The Unix Cluster has following characteristics:

  * A single account grants you access to all computers.  Once you've logged into one of the computers, gaining access to the other computers usually does not involve re-entering your password.

  * There's a single ``home'' directory for each user which is available on all the computers.  You can edit your files on one machine and compile and run them on another machine.

  * There's a single E-mail address for each user, and a single system file for E-mail.

  * Most of the file systems are shared between computers.

  * Most of the same software is available on all the computers.

  * Various other services are provided by the cluster and are available to users from any computer.  These include: printing, news, web publishing, anonymous ftp, fax transmission and reception.

This means that it usually doesn't much matter which computer you use. Typically, you might be content just to use a single computer. However, if that computer becomes too slow or is scheduled to be down, then you can move to another computer more-or-less transparently.

Members
=======

The following computers are members of the Unix Cluster

Name   Make   Model (CPUs)   Operating System
lyman   Sun   Sparc 10-521 (2)   Solaris 2.5.1
carl   Sun   Sparc 10-521 (2)   Solaris 2.5.1
orion   Sun   Ultra 2 (2)   Solaris 2.6
lupus   Sun   Sparc 10-421 (2)   Solaris 2.5
ron   Sun   Sparc 20   Solaris 2.5
tom   Sun   Sparc 10-41   Solaris 2.5.1
frodo   Digital     OSF1 4.0b
wave   Digital     OSF1 4.0b
hydra   Digital   (4)   OSF1 4.0d
tern   Intel   Pentium 166MHz   Linux 2.0.36
jupiter   Digital     OSF1 4.0d
venus   Digital     OSF1 4.0d
mars   Digital     OSF1 4.0d
saturn   Digital     OSF1 4.0d
mercury   Digital     OSF1 4.0d
neptune   Digital     OSF1 4.0d
taurus   Sun   Enterprise 450 (2)   Solaris 2.6
solo   Sun   Sparc 5   Solaris 2.6
ead01   Sun   Ultra 5/10   Solaris 2.6
ead02   Sun   Ultra 5/10   Solaris 2.6
ead03   Sun   Sparc 20 (2)   Solaris 2.5
pppl   Sun   Sparc 2   SunOS 4.1.4

The fastest computers in the Cluster are taurus and the ``planets'' (venus, mercury, etc.). Use these for your heavy number crunching needs. pppl (which is also known as pobox) is reserved for handing E-mail, and you should not normally use this computer.  The other computers are fine for interactive use.

The full Internet names for these computers are formed by adding ``.pppl.gov'' to the name, e.g., ``taurus.pppl.gov''.  (But ``pppl.pppl.gov'' is really called ``pppl.gov''.)

Accounts
========

For an account on the Unix Cluster, contact Lena Scimeca (x2833, E-mail: unixadmin@pppl.gov).  She will need to know:

 1. Your full name

 2. Your prefered username.  Your username is limited to 8 characters.  By default, the choice of username is your first initial and last name; however, if that is more than 8 characters, or if you already have accounts under another username, you may want to choose another username (such as your last name only or just your initials).

 3. whether you already have an account on NERSC (and if so, what your username is there).

You will be given a home directory when your account is created which will be called /u/USERNAME, however in many contexts you can also refer to your home directory by the abbreviation ~. (Similarly you can refer to home directory of user jsmith either with /u/jsmith or ~jsmith.)

By default, there's a quota of 20MB on your home directory.

Passwords
=========

Your account will be assigned a password initially.  You should change this as soon as possible after getting your account set up.  On the Unix computers, type

     passwd

while on any of the computers in the Unix Cluster (except for Linux computers).

You will be prompted for your old password and asked to select a new password (which you need to enter twice, to guard against typos---the passwords are not echoed on the screen).  This changes your password on all the Unix Cluster computers.

Here are some guidelines for choosing a password:

  * Passwords must be at least 6 characters long.

  * Passwords must be changed at least once a year.

  * Passwords should not be a word, username, or personal name.

In addition, the following recommendations will make your password more difficult to guess:

  * The longer the better---however, only the first 8 characters count on Unix systems.

  * Use the password generator on the VAX.  (Type SET PASSWORD/GENERATE=6 on the VAX cluster and keep hitting RET until you see a password you like.  Type CTRL-z to get out.)

  * Mix upper and lower case; include digits or punctuation.

E-mail
======

E-mail is the standard way for users to communicate with one another on computer systems.  In addition messages from the computer (indicating, for example, that you need to change your password) are sent via E-mail.

On the Unix Cluster, your E-mail address is simply

     USERNAME@pppl.gov

Important: You must ensure you can (and do) read mail sent to this address.  You have three choices for how your mail is handled:

 1. You leave the mail on the Unix Cluster and you use some mail reader on the Unix Cluster to read your mail.

 2. You leave the mail on the Unix Cluster and you use a POP client on a desktop computer (e.g., Eudora on a Mac) to access your mail via a POP server on pppl.gov.

 3. You have your mail forwarded to another computer system.

Forwarding
----------

Forwarding of mail is governed by a forward file.  On traditional Unix systems, this is called ~/.forward.  However on the Unix Cluster, you should place your forwarding address in /usr/mail/.forward/USERNAME.  This file should contain the complete E-mail address of where you want the E-mail sent.  E.g.,

     echo zarnstorff@vaxcluster.pppl.gov > /usr/mail/.forward/zarnstor

A partial verification of the forwarding is provided by finger

     $ finger zarnstor@pppl.gov
     ...
     Mail forwarded to zarnstorff@vaxcluster.pppl.gov.

However, you should also test it in case you've created a forwarding loop (where the mail is sent around in circles).  Send yourself some mail and verify that it arrives OK.

If you want to stop the forwarding of mail, just delete /usr/mail/.forward/USERNAME.

If forwarding doesn't look like it's working, it may be that a system-supplied E-mail alias is over-riding it.  Check with unixadmin@pppl.gov.

For more information see forward,4.

Aliases
-------

For those people whose usernames do not conform to the standard of initial+lastname, there should nevertheless be an alias which directs E-mail from initial+lastname to the correct destination.  For example, John Krommes' username is krommes and so his E-mail address is krommes@pppl.gov.  However jkrommes@pppl.gov is an alias of krommes@pppl.gov.  You can verify the existence of such an alias by using finger:

     $ finger jkrommes@pppl.gov
     The alias jkrommes expands to John Krommes <krommes@pppl.gov>.

Aliases are set up by a system administrator.  If you think the aliases for you are not correct, send E-mail to unixadmin@pppl.gov.

Getting Help
============

Since Unix is now more than 20 years old, there are several disconnected ways in which documentation is provided to the user.  The main ways are man pages, info, the web, command-line prompts and other on-line aids, specialized document viewers, miscellaneous files, and finally printed manuals and books.  Finally, it sometimes necessary to ask someone for help.

man pages
---------

The original way in which most aspect of Unix was documented was via ``man'' pages.  Traditionally these were bound into ``sections'', with section 1 containing user commands, section 2 containing system calls, section 3 containing library routines, etc.  A man page designation ls,1 then documents the command ``ls'' in section 1.

The simplest way of reading a man page is via the command man,1.

info
----

Documentation on the web
------------------------

Other documentation
-------------------

Human Help
----------

The makeinfo and texinfo-format-buffer http://w3.pppl.gov See ls,1. commands transform a Texinfo file such as this into an Info file; and TeX typesets it for a printed manual.