What Is Ubuntu?

Ubuntu is a new distribution within the Linux world. However, despite only having been around since the middle of 2004, Ubuntu has rapidly become popular among both new and seasoned users. The reasons are many, but can be pinned down to ease of use and careful development to ensure maximum compatibility. One of Ubuntu's key beliefs is that everything "should just work," and to a large extent this is true. Ubuntu itself is based upon the GNOME window manager, with a standard set of application software and the means to access all 16,000+ applications from the wider Debian software universe.

As you learn in this chapter, Ubuntu is one of the most up-to-date and rapidly moving Linux distributions available on the Internet. Here, you see why Ubuntu is a good choice for a variety of computing environments and how, when combined with advances provided by the latest Linux kernel, it can provide support for a huge range of users from the academic, home, small business, and up to corporate and large-enterprise users.

Inside Ubuntu

A copy of the Ubuntu distribution requires only one CD, something of a rarity in the Linux world. On this CD, you get everything you need to get up and running, including application software as well as several programs that give you direct access to the 16,000+ items of software available through the Debian software universe. Ubuntu is also available on a DVD installation, which includes hundreds of extra packages that you can install by using synaptic.

Ubuntu provides a base, or core, framework operating system and desktop composed entirely of free software. Ubuntu includes the Human desktop theme and by default ships with the GNOME window manager in place. If you prefer Xfce or even KDE, you can easily obtain and install Xubuntu or Kubuntu, both of which have the Ubuntu distribution at their core but use alternative window managers.

From a single CD to a huge repository of software, you can expect to spend long hours exploring the software on offer from Ubuntu. The synaptic package manager makes installing and maintaining software an easy exercise, meaning all you have to do is find out what is on offer.

Note

Read more about GNOME and KDE in Chapter 6, "The X Window System."

Ubuntu provides the latest version of the X Window System and its server, X11R7, which sports improved and integral font handling. The Linux desktop has never looked better, and you will notice the difference when you browse the Web, use one of the dozen or so word processors and text editors available with Ubuntu, or view text at the command line in a terminal window.

Ubuntu also comes with a suite of management and administration tools that enable you to administer every part of your system.

Table 1.1. Ubuntu Graphical Administration Tools

Name	Description
network-admin	Creates, edits, and manages network devices
synaptic	Manages software and updates
gnome-cups-manager	Configures local and network printers
users-admin	Manages users and groups
update-manager	Provides one-click access to system updates
disks-admin	Works with and configure connected disks
gnome-language-selector	Configures Ubuntu to use one of many languages
services-admin	Manages system services
shares-admin	Creates and manage shared directories with Samba and NFS
system-config-language	Sets system language
gnome-mouse-properties	Configures mouse type and features
gnome-system-monitor	Monitors system activity to aid troubleshooting and maintenance

Ubuntu includes Internet programs such as Mozilla's open source web browser, Firefox, along with productivity applications such as Ximian's Evolution (a mail, contact, and calendaring client) and OpenOffice.org (a Microsoft-compatible open source office suite). You'll find all these and many more applications on this book's DVD.

Other major features are the inclusion of the latest GNU gcc compiler system, supporting C/C++ language program development. You also get the newest version of the Apache web server, and the Common Unix Printing System (CUPS), which supports more than a thousand different printers.

Ubuntu is slated for upgrades at least twice a year, according to the Ubuntu Community. In reality, however, work never ceases on the distribution because of open source developers supplying Ubuntu with software package upgrades, security updates, and bug fixes. Ubuntu's free, online upgrade system is available via the Internet. With the power of Debian, direct upgrades between different versions of Ubuntu are supported. Typically, you should expect to be able to upgrade to a version that is two releases ahead of the one you are running, so you should not need to worry about upgrading until at least version 7.04 is released! Ubuntu 6.06, also known as the Dapper Drake, has had some extra polish added to it and a commitment to provide support for a full 5 years, something of a rarity in the Linux distribution community.

As a Ubuntu user, you can obtain the latest software for your system at any time using a variety of commands and software management tools:

synaptic The powerful graphical front end to apt-get, synaptic enables you to easily browse and quickly install any required software from the Ubuntu/Debian repositories.

apt-get The command-line tool favored by Debian purists, apt-get is extremely fast and very versatile, allowing easy upgrades between distributions.

dpkg The Debian package management tool, which works at a lower level than apt-get.

Distribution Version and Kernel Numbering Schema

There is a specific numbering system for Linux kernels, kernel development, and Ubuntu's kernel versions. Note that these numbers bear no relation to the version number of your Ubuntu Linux distribution. Ubuntu distribution version numbers are assigned by the Ubuntu developers, whereas most of the Linux kernel version numbers are assigned by Linus Torvalds and his legion of kernel developers.

To see the date your Linux kernel was compiled, use the uname command with its -v command-line option. To see the version of your Linux kernel, use the -r option. The numbers, such as 2.6.15-14, represent the major version (2), minor version (6), and patch level (15). The final number (14) is the developer patch level and is assigned by the Ubuntu developers.

Even minor numbers are considered "stable" and generally fit for use in production environments, whereas odd minor numbers (such as a Linux 2.7 source tree, not yet in existence) represent versions of the Linux kernel under development and testing. You will find only stable versions of the Linux kernel included with this book. You can choose to download and install a beta (test) version of the kernel, but this is not recommended for a system destined for everyday use. Most often, beta kernels are installed to provide support and testing of new hardware or operating system features.

Features of the Ubuntu Install

Installing Ubuntu is now extremely easy thanks to the integration with a Live CD. Before you decide to install, just boot up using the CD to make sure that your system can handle Ubuntu. Once you are happy with it, you can use the simple GUI installer that Ubuntu supplies to install Ubuntu straight to your hard drive. You do get a few options before you boot the live CD, which are listed below:

• Testing the installation media Useful for testing the integrity of your copies of the Ubuntu CD-ROMs/DVD. If you download .iso images of the Ubuntu CD or DVD, you can also use an MD5SUM client to compare the prepublished checksums for the media against your .iso files.

• Testing your PC's memory Useful for ensuring that your PC is in good form with functioning memory. Linux will use every available byte of RAM, and you should ensure that you do not run into problems after the operating system is installed.

• Rescuing the system In instances where a boot loader configuration has failed, or for some reason the system will not boot, you can use the installer to boot to a rescue mode; you can then mount the existing file system and rescue data or reconfigure the system to resolve the problem.

• Specifying hardware workarounds You can use various options at the installer command line to get around problematic or unsupported hardware posing an obstacle to your install.

• Specifying an install method You can install Ubuntu from a hard drive partition or over a network using FTP, NFS, HTTP, or virtual networking.

See Chapter 3, "Installing Ubuntu," for specific details about various installer options.

Ubuntu installs a preselected choice of software as standard, allowing you to add to this depending on your specific requirements. Unlike other distributions, there are no "Server" or "Workstation" options; instead, Ubuntu is designed with flexibility in mind and comes with the uber-efficient apt-get and synaptic packages. This combination of tools enables you to acquire and install new software with little hassle and opens up a whole world of software to you.

See Chapter 2, "Preparing to Install Ubuntu," for some important considerations to help you prepare to install Ubuntu. See Chapter 3 to learn how to install using a CD-ROM/DVD, a hard drive, or a network.

Ubuntu File System Features

Ubuntu also uses the ext3 file system, developed by Dr. Stephen C. Tweedie and used by the majority of Linux distributions. ext3 supports a form of low-level storage data handling known as journaling, previously available only under expensive computer platforms. Journaling is accomplished using a variety of techniques, but the end result aims to ensure that data remains intact on the disk despite a system crash, a power outage, or other mishap.

However, because Ubuntu is designed to be flexible and accommodating of all new Linux technologies, you can use other file systems for your workstation or server. This includes IBM JFS, a journaled file system designed for servers and used on many enterprise-level platforms. If you want to take advantage of fast restarts and enjoy good performance and reliability, you can use JFS as an alternative to ext3. However, ext3 offers benefits such as quick switching between legacy ext2 file systems and widespread use in the Linux community.

Note

You can find more information about IBM's JFS file system for Linux at http://oss.software.ibm.com/jfs/.

Note

Read Dr. Stephen Tweedie's presentation, "EXT3, Journaling File System," at http://olstrans.sourceforge.net/release/OLS2000-ext3/OLS2000-ext3.html for more details.

Other journaling file systems should be supported by Ubuntu (such as reiserfs) and have similar features.

Ubuntu also supports the creation of large RAID arrays, both via software using one or more storage devices and using hardware with specific device controllers. You can also use logical volume management (LVM), a sophisticated file system handling feature that allows parts of the file system (directory layout) to span one or more portions of separate physical storage media. This feature also allows resizing of the resulting partitions if system resource requirements change after initial configuration, and while the pertinent file systems are unmounted or mounted.