Redhat Unwrapped

Introduction

RedHat's GNU/Linux comes set up to perform a huge number of server tasks straight out of the box. To the first time user it can be very daunting trying to tackle the configuration of these servers. RedHat Unwrapped shows the first time user how to get underway with their brand new RedHat system.

Initially however I should like to make some remarks on the target audience. The aim of RedHat unwrapped in purely to be a getting started document. It assumes some familiarity with Unix in general but no knowledge of systems administration is required. I must also assume that you are sitting in front of a working RedHat system. Since each topic contains only the minimum information to get RedHat users started.

My motivation to write this document is the hours it can sometimes take to learn one vital piece of information required to get going. The aim of this document is simply to allow the user to get stuck in. Once they are stuck in then it is time for them to read a good book or the documentation supplied with the package.

Contents

• PostgreSQL
• SAMBA
• XFS

PostgreSQL

PostgreSQL is an advanced object/relational database management system (DBMS) that supports almost all SQL contructs.

RPMS

postgresql
postgresql-clients

Config Files

/var/lib/pgsql/ (directory)

Unlike most other services PostgreSQL does not come prconfigured. It requires some small configurations before the backend server will even start. This is very much a quick start guide. The sort that will help someone get to the SQL quickly. It does not pretend to be any sort of general admin. guide.

First we must initialise the database. PostgreSQL has its own administrator user, postgres. In fact it does not permit root to administer a Postgres database system. In order to initialise the database we must become the postgres user. Use su -l postgres to do this (the -l is important), initially the postgres user can not log in so you must run su from a root shell.

We can not initialise the database system. We are not creating a database, merely the area in which all databases will be stored. The initdb command uses the templates in the pglib directory to initialise the database in the pgdata directory. The line to accomplish this in RedHat Linux is as follows.
initdb --pglib=/usr/lib/pgsql --pgdata=/var/lib/pgsql

Finally we have to permit some users to use the database system. This is accomplished using the createuser command. After running this command you will asked for the users name. This should be the login name of the desired user. The system will then look up that users UID and request confirmation, unless you have a (very) good reason you should accept this. Finally you will be quized about the privalidges of the user. Generally it is worthwhile allowing users to create databases.

The database system is now ready to go. In a shell belonging to a user added using createuser you are able to simple create a database using the createdb command. It does not need any arguments. psql is a query system, again for now it can be started without any arguments.

Now all you need it for someone to teach you SQL!

SAMBA

Samba is the software used to support the Server Message Block (SMB) protocol used throught the world of Windows. I use Samba to save myself the expense of buying another printer.

RPMS

samba
Note that the errate for RH6.0 introduces a second RPM, samba-client

Config Files

/etc/smb.conf
/etc/smbusers

Server

As always we must insure the Samba service is running. Use a tool such as ntsysv or control-panel to check that smb is active.

Samba is preconfigured to share home directories and printers to any user listed in /etc/passwd.

The diffuculty in making Samba to work lies not on your GNU/Linux workstation but with your Windows machine. The following paragraph applies only to Win95/98 users. Others will have to provide their own translations.

Presuming your network card is installed properly, that you have Client for Microsoft Networks and that TCP/IP is working properly (does ping work) then you should be able to see your GNU/Linux machine from the Entire Network part of the Network Neighbourhood. If you double click on your machine you will be asked for a password but not a usercode. This can be very confusing. The Windows machine is suppling the usercode automatically, the name you logged Windows with. The file smbusers is a set of aliases to convert Windows usernames into Unix ones. The file format is explained at the top of the file.

XFS

The X Font Server (xfs) is a font rendering service for the X windows system. It replaces the in-built font rendering that the X server can perform. Font servers need not be on the same machine as the X server. They can support a wider variety of fonts (ie truetype).

RPMS

XFree86-xfs

Config files

/etc/X11/fs/config

Warning: Redhat 6.0 as shipped has problems with the XFS system (it uses a negative TCP/IP port). In order to correct this either use the upgrade in the errata or modify /etc/rc.d/init.d/xfs and change the port from -1 to 7100. You will also have to make a similar change to /etc/X11/XF86Confg.