As a long-time fan of SuSE Linux, I somehow managed to miss the Ubuntu bandwagon. Now I know what I was missing. I recently replaced SuSE 10.1 with Ubuntu 6.06, also known as Dapper Drake, on my main PC in a matter of minutes, and am now enjoying a clean, feature-rich computing environment that is easy to configure and just works.
It was such a nice change, I began to wonder how well Ubuntu would run on some of my older PCs. Alas, the resulting installations were a little slow, and in one case installation failed completely. But a little research turned up tricks to get Ubuntu sprinting even on antiquated systems. Here are a few basic things I did to adapt Dapper Drake to old hardware.
Get the alternate CD: To install Ubuntu, you must first download the live-CD version from one of the mirror sites listed on Ubuntu's page (www.ubuntu.com/download) and burn it; you then boot your PC with the disc, and install. However, PCs with less than 192MB of RAM may not be able to boot with the standard CD, so you'll need to download the alternate install CD (lower down on the same mirror page) instead - see Figure 1.
Cut down on the eye candy: Ubuntu's default graphical interface is the Gnome desktop environment. Though it's very slick, it can be slow on older graphics adapters. One way to speed it up is to avoid complex themes and backgrounds. Choose System-Preferences-Theme, select a lightweight theme like "Simple", and click on Close. You can also save memory and avoid swapping to disk by skipping desktop background images: right-click the desktop, choose Change Desktop Background, select No Wallpaper, and click Finish.
Not all roads lead to Gnome, of course - you may prefer to use the KDE environment with Ubuntu instead. The Kubuntu distribution (www.kubuntu.org) replaces Gnome with KDE but otherwise installs and works much like Ubuntu. You can also just add KDE to an existing Ubuntu installation using Synaptic Package Manager, and choose one or the other environment from the log-in screen's Options menu. Like Gnome, KDE can be slow on older hardware. To speed it up, choose Settings-Control Center in the KDE menu, click on Theme Manager under "Appearance & Themes", click on Style under "Customize your theme", select the Effects tab, and uncheck "Enable GUI effects". Then click OK and Apply to finish.
Try a slimmed-down window manager: Another way to accelerate Ubuntu is to choose a window manager that is fundamentally less hardware hungry, such as the Xfce 4 Desktop Environment. You can add Xfce to your existing Ubuntu installation through Synaptic, or download the Xubuntu distribution (www.xubuntu.org), which by default installs Xfce in place of Gnome. Xubuntu is also a good choice for machines with very little memory, as Xubuntu's alternate install CD works on computers with less than 128MB of RAM.
Dig deeper: Performance is more than skin deep. Ubuntu's online forums contain additional tips and how-tos on regaining even more precious processor cycles by disabling unneeded services, speeding up Firefox, deleting unnecessary files, optimising OpenOffice, and more. Start with the "Improve performance in Ubuntu" thread at www.ubuntuforums.org/showthread.php?t=189192/ (see Figure 2) and don't stop until Ubuntu has reached maximum speed.
Linux has a reputation for being relatively impervious to attack via the Net. But is it really immune to the threats that stalk Windows? The answer has long been, and still is, a qualified yes. Sure, occasionally viruses, worms and rootkits are written specifically to compromise Linux systems. But if you avoid a couple of major blunders, those relatively few threats are unlikely to do you any real harm. To sleep utterly soundly, however, you may still need to take some steps to malware-proof your Linux system.
The first reason your Linux system is probably safe from attack is that recent versions of Linux (kernels 2.4 and 2.6) include a built-in firewall called "iptables" that simply drops all uninvited incoming connections by default. If a worm or a person tries to break into your Linux box from afar, or not so afar, iptables simply turns away and ignores the incoming connection - the attacker won't know whether a system even exists at the attacked address.
If you don't run mail, Web, FTP, or other servers on your Linux system, you'll probably never need to modify iptables' default settings. However, if you use the Samba server suite to enable file and printer sharing with other local systems, you will have to enable incoming connections to the Samba server in iptables - see Figure 3.
In SuSE 10.1, the Yast2 configuration tool lets you make this change in a few clicks: select Firewall in the "Security and Users" section, click Allowed Services in the left panel, pick Samba Server from the "Service to Allow" menu, and then click Add-Next-Accept to make the change. If your distribution lacks a similar interface, try Luigi Genoni's graphical iptables configuration interface, Knetfilter (http://expansa.sns.it:8080/knetfilter/). And, of course, you can configure iptables from the command line; Troy Johnson's Samba and IPTables page (http://troy.jdmz.net/samba/fw/) shows you how.
By default, most Linux distributions wisely set you up as a lower-privilege user, with a type of account that generally can't allow malicious code to take over the system. Were you to somehow permit a Linux virus or worm to run on your computer, the fact that you are not logged in on the all-powerful root account prevents the malware from attacking the system's (and other users') files. That's why you typically have to log in as root (with the root password) to change Linux system configurations. In contrast, the default Windows XP user account is the full-privilege administrator, which gives viruses and other threats greater leeway to infect and damage the PC.
However, should someone you know lose their head and log in as root, and then run a program that happens to be infected with one of the few Linux viruses known to exist in the wild, that virus could definitely destroy or steal user data. And even if you think you're smart enough to avoid infection, the files moving through your mailbox, Samba file shares (shared files mounted as drives), and other storage mechanisms could still contain viruses destined to infect other systems. These are valid reasons why you might want to use antivirus software on your Linux computer.
Although commercial Linux antivirus products exist, save your money and start with one of several excellent free utilities instead. Even better, pick one that is not only free but open source: the delightfully named Clam AntiVirus (www.clamav.net/binary.html#pagestart). In addition to binary packages (no compiling necessary) for most major Linux distributions, ClamAV is also available for Windows and Mac OS X.
If you'd prefer antivirus software with a commercial track record, try the Linux version of Grisoft's renowned AVG Anti-Virus Free Edition (http://free.grisoft.com/). Because of Linux's inherent safety, the system you save may not be your own, but you'll be doing your part to curb malware altogether.