Introduction

System Administration With Webmin

A brief overview of new era administration

tool

Prepared by

Henry Batula 12539114

Ni Xiao 12640223

Peter Greenup 12645736

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What is Webmin?

Webmin is a web-based interface for system administration for Unix/Linux. Using any browser that supports tables and forms (and Java for the File Manager module), you can setup user accounts, Apache, DNS, file sharing and so on

Often considered equivalent to windows control panel

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What is Webmin (cont’d)

It is a user administration tool written by Jamie Cameron in Perl that is designed to be lightweight, functional, and easily extensible

It has been translated to 14 languages at the moment It has been embraced by a number of hardware and

operating system vendors as the default system administration tool(Linux-Mandrake 7.0)

It is extremely portable, offering support for more than 25 different Unix/Linux Operating Systems

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What is Webmin? (cont’d)

It is very easily extended to support new features and options, due to it's open and well documented API

It also happens to be a fast and easy to use tool for general Unix/Linux system administration

It allows easy addition of new modules without changing any of the existing code

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What is required

A simple web server, and a number of CGI programs which directly update system files like /etc/inetd.conf and /etc/passwd.

The web server and all CGI programs must be written in Perl version 5. This means that you only need a Perl binary to run it.

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Who Webmin is For

It is an excellent tool for both novice and experienced system administrators

When run from a local machine, it can help new users become familiar with the capabilities of a Linux system.

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Sections within Webmin

The individual modules of webim are found in 5 different sections.

• Webmin• System• Servers• Networking• Hardware• and Others

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Interface of Webmin

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Webmin modules

It uses modules, which are similar to plug-ins, and easily allow you to extend the base functions of Webmin.

It is divided into a number of modules that each allows to administer a single aspect of system

There are Currently 127 Modules The standard modules provide a graphical interface

for: Apache, Squid, Bind, NFS, man pages, Sendmail, Postfix, Samba

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admin

Scheduled Cron Jobs BIND 4 DNS Server

NFS Exports Internet Services and Protocols

Bootup and Shutdown Actions Disk and Network Filesystems

Samba Windows File Sharing Users, Groups and Passwords

Partitions on Local Disks Running Processes

Webmin Configuration Disk Quotas

Software Packages PPP Usernames and Passwords

Webmin Users Apache Webserver

Printer Administration BIND 8 DNS Server

Sendmail Configuration Squid Proxy Server

File Manager Network Configuration

DHCP Server Majordomo List Manager

Firewall Configuration

Common Modules from Webmin 0.74 Modules

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Supported Operating Systems

Sun Solaris NetBSD DEC/Compaq OSF/1

Cobalt Linux Mandrake Linux Mandrake Linux Coprporate Server

Caldera OpenLinux eServer BSD IBM AIX

Redhat Linux HP/UX SCO UnixWare

Slackware Linux SGI/UX SCO OpenServer

SuSE Linux Corel Linux TurboLinux

MSC Linux LinuxPPC Xlinux

Cendio LBS Linux Linux From Scratch Trustix

Ute Linux Lanthan Linux Trustix

Cendio LBS Linux FreeBSD OpenBSD

Debian Linux SGI Irix Mac OS Server X

Delix DLD Linux Conectiva Linux  

Some of Webmin supported operating systems

Installation of Webmin

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Installation of Webmin

Firstly check to see if it is currently installed. Do a search for the webmin module. Webmin is included with many linux operating systems, so may appear on an installation disk.

Installation requires that Perl 5 is already installed (this is usually included with most versions of linux).

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Installation (Cont’d)

L-M animation of finding package.

(you may need to wait a few seconds for the animation to start).

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Otherwise it can be downloaded from www.webmin.com There are a couple of different versions available, choose the one which best suits your current system. Approximate file size is 3.6 to 4MB

If installing the RPM package run the command: rpm -U webmin-0.87.rpm

If using the Solaris package run the following command: pkgadd -d webmin-0.87.pkg

Begins with root username and password.

Installation of Webmin (Cont’d)

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Installation Checks

Please wait for animation of Webmin after install.

Webmin is seen as a new service in the linuxconf control panel

Ktail messages shows that webmin starts automatically after install.

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Installation Checks (Cont’d)

Check the following functions for Webmin: Stop Start Restart

The "messages" log will show the status.

Please wait for animation.

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Logging on

Open a web browser such as Netscape or IE, on any machine with access to the server you wish to log onto.

Browse to the port 10000 of the IP address or hostname. (as shown below)

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Logging on (Cont’d)

Animation of logging onto the service.

Example Modules

A brief description of some of the commonly used modules.

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Webmin main tab

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Webmin Configuration

This section give the user control of the webmin setup. Allowing the adjustment to the following areas.

IP address control Password settings Interface control Language used Modules included

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Webmin Configuration (Cont’d)

Animation of access to IP address

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System Tab

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System modules

Bootup and shutdown• as name suggests

Users and Groups• displays all users names, id’s home directory etc.

• allows editing of user settings Manual Pages

• extensive help pages

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System modules (Cont’d)

Cron Jobs• This is one process that is greatly simplified by the

webmin interface.

• Cron is a daemon that runs constantly on most unix machines. Allows for the scheduling of processes to be run at set times eg. backups or scans.

• Lists all scheduled jobs

• Control access of users to cron jobs

• Add a new scheduled item

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System modules (Cont’d)

Cron job screen sample

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System modules (Cont’d)

Software packages View all installed

packages Search for

installed packages Install new

packages

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System modules (Cont’d)

Install package screen sample

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System modules (Cont’d)

FileSystem Management It provides permission to

• mount,

• dismount,

• create,

• edit, and

• delete 14 different filesystems

To get started, • click the Disk and Network Filesystems

Webmin displays a list of available filesystems

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System modules (Cont’d)

File System Management Display screen will show the

• mount point,

• filesystem type,

• device or location whether it is • mounted, and

• listed in /etc/fstab.

To edit one of the listed file system, • click its mount point, listed in the first column

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System modules (Cont’d)

File System Management To add or create a new filesystem,

• first select its type from the drop-down list box

• then click the “Add” button

The Create Mount and the Edit Mount screens are similar except that it has to be filled it out

Select the “Don't Save” button• to prevent an entry for the swapfile from being added to /etc/fstab

• the swapfile will be named, imaginatively, /tmp/swapfile

Click the “Create” button to activate the changes

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System modules (Cont’d)

The display screen After making changes,

click• the “Apply” button to

update the /etc/fstab file • activate the changes.

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System modules (Cont’d)

Running Processes Webmin's process manager

• resembles a browser-based version of the famous top utility• allows to execute an arbitrary command• screen is obtained by

• clicking the “Running Processes” icon

The display is sorted either• by process ID or by selecting the link of• username, • memory usage, and• CPU time consumed

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System modules (Cont’d)

Running Processes Can be used after filling in the searching criteria

• by clicking the corresponding search button

Criteria Description

Owned by Enter a user name

Matching Enter a string

Usage % CPU Enter between 0 and 100

Using filesystem Select a filesystem

Using file Enter a filename

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System modules (Cont’d)

Running Processes Can be used to change process priority

• click a PID from either the main listing or a search screen

• select a new priority (called a nice level)

• then click the “Change” button

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System modules (Cont’d)

Running Processes Common process signals with webminSignal Description

INT Sends a keyboard interrupt (Ctrl+C)

QUIT Terminates the process.

ABRT Terminates the process and creates a memory dump

KILL Terminates the process

TERM Terminates the process

STOP Stops the process, but does not kill it

CONT Resumes a stopped process