3.2 To YaST or not to YaSt

3.2 To YaST or not to YaSt

Yet another Setup Tool (YaST) is the main administration instrument on a SuSE Linux distribution. It combines most common administration tasks . YaST is not distributed under the General Public License (GPL), but has its own license; see:

http://www.suse.de/en/private/support/licenses/yast.html

YaST can be used in graphical mode or in a terminal window with ncurses. It is modular and opens new windows in a graphical mode for each module. You can get the list of available modules on your system (and shortpaths) by issuing the yast2 -list command, as shown in Example 3-1.

Example 3-1. AvailableYaST modules and shortpaths

# yast2 -list

Available modules:



autoyast

backup

bootfloppy

disk

dns

dsl

firewall

hwinfo

idedma

inetd

inst_source

isdn

joystick

keyboard

lan

language

ldap

lilo

lvm_config

mail

modem

mouse

nfs

nfs_server

nis

nis_server

online_update

powertweak

printer

profile-manager

proxy

restore

routing

runlevel

security

sound

sw_single

sysconfig

timezone

update

users

vendor

x11

YaST is easy to use and in graphical mode, it visualizes complicated tasks in a comprehensible way. We recommend using it, for example, for partitioning, for the first setup of Logical Volume Manager (LVM), and so on. YaST will prevent you from making certain errors and at least warn you in critical cases.

YaST makes changes to the system directly; it does not maintain its own configuration database (as was the case in older versions of SuSE). This means that we can combine administration by editing appropriate configuration files and through YaST, without producing system inconsistencies. For example, if we edit /etc/resolv.conf and run yast2 dns after that, it will show the current entries and allow us to edit them.

On the other hand, we do see some disadvantages to using YaST in a network environment:

• YaST does a great deal of logging, but it does not log which files are changed and which commands are called to achieve the particular task. You can find YaST logs in /var/log/YaST2/y2log. It differs from the AIX administration tool smit it that you cannot use the information in the logs for task automation through scripting.

• YaST is a single system administration tool, so you can only change the system you are using; you cannot run the same command on different systems.

• YaST does not provide a "bash mode", so you cannot include the task that YaST should complete in the command line arguments or in a script.

• Some modules provided by YaST are incomplete; that is, they do not offer all possibilities and are restricted in functionality. For example, it is not possible to change RAID devices, to assign a whole physical disk to LVM, or to manage LDAP users through YaST.

Tip

We used tripwire to find out which files YaST is changing. To use tripwire, you need to generate a tripwire database first, then do anything with YaST and run tripwire again to see which files are changed

3.3 Web-based system administration (Webmin)

Webmin is a Web-based system administration tool for most UNIX systems. You need a frame-capable browser with Java support (this is only required for some modules).

Webmin has a modular structure it is easy to customize. Webmin has a built-in ability to delegate administration tasks to non-root users.

3.3.1 Webmin installation

To install Webmin, download the tar.gz file from:

http://www.webmin.com

Uncompress and untar it to the /opt directory.

Run the setup.sh script and answer the dialogs as shown in Figure 3-2.

Important

In a production environment, we recommend that you enable ssl support and use secure password (keep in mind that the main webmin user has all the root privileges!).

lpar3:/opt/webmin-1.120 #

./setup.sh

***********************************************************************

*            Welcome to the Webmin setup script, version 1.120        *

***********************************************************************

Webmin is a web-based interface that allows Unix-like operating

systems and common Unix services to be easily administered.



Installing Webmin in /opt/webmin-1.120 ...



***********************************************************************

Webmin uses separate directories for configuration files and log files.

Unless you want to run multiple versions of Webmin at the same time

you can just accept the defaults.



Config file directory [/etc/webmin]:

Log file directory [/var/webmin]:



***********************************************************************

Webmin is written entirely in Perl. Please enter the full path to the

Perl 5 interpreter on your system.



Full path to perl (default /usr/bin/perl):

Testing Perl ...

Perl seems to be installed ok



***********************************************************************

Operating system name:    SuSE Linux

Operating system version: 8.1



***********************************************************************

Webmin uses its own password protected web server to provide access

to the administration programs. The setup script needs to know :

 - What port to run the web server on. There must not be another

   web server already using this port.

 - The login name required to access the web server.

 - The password required to access the web server.

 - If the webserver should use SSL (if your system supports it).

 - Whether to start webmin at boot time.



Web server port (default 10000):

Login name (default admin):

Login password:

Password again:

Use SSL (y/n): n

Start Webmin at boot time (y/n): y

***********************************************************************

Creating web server config files..

..done



Creating access control file..

..done



Inserting path to perl into scripts..

..done



Creating start and stop scripts..

..done



Copying config files..

..done



Configuring Webmin to start at boot time..

Created init script /etc/init.d/webmin

..done



Creating uninstall script /etc/webmin/uninstall.sh ..

..done



Changing ownership and permissions ..

..done



Running postinstall scripts ..

..done



Attempting to start Webmin mini web server..

Starting Webmin server in /opt/webmin-1.120

..done



***********************************************************************

Webmin has been installed and started successfully. Use your web

browser to go to



  http://lpar3:10000/



and login with the name and password you entered previously.

http://lpar3.residency.local:10000/