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Live CD Linux Distributions

Creative solutions to your everyday problems

Many people feel that if they get something for free there is no real value in it, but that's not always the case. Free doesn't always equate to low quality or "cheap." Especially when it comes to open source and free software.

I am often fascinated by the caliber of the many open source and royalty-free applications available and useful to a variety of organizations, from business to government to education. In homage to those people who develop and donate their applications to the community, I am focusing on a collection of tools from the open source community that can be used to solve common PC problems. These solutions are not only without licensing fees, they are adaptable to different needs of various classifications of users. I chose to focus on Linux-bootable CD distributions and the utilities included with them for a range of applications from bioinformatics to rescuing PCs destined for the scrap heap or ailing due to viruses.

The best way for the new Linux user to take advantage of these tools is by virtue of a bootable Linux distribution because it won't require you to install Linux and will allow you to use an existing PC that may already have an operating system on it. Also, in many instances having a portable operating system is the key to solving your problems.

KNOPPIX: Free Operating System, Big Savings

I have mentioned on occasion the KNOPPIX Linux Distribution (www.knoppix.com), which runs from a bootable CD on a wide variety of PCs with or without all the working parts. KNOPPIX is particularly attractive because it includes a working operating system and thousands of applications, and is as easy to obtain over a broadband connection. Not only is the KNOPPIX downloadable from numerous Web sites but via the Bit Torrent (http://bitconjurer.org/BitTorrent) peer-to-peer file sharing network, an excellent and legitimate use of p2p technology. I am using for the purpose of this article the latest release, version 3.4, of KNOPPIX. (You can find out more about KNOPPIX at www.knopper.net/knoppix-info/index-en.html#description

).

Repurposing Workstations

In many businesses PCs are taken out of service as part of scheduled upgrade plans. Frequently these machines are decommissioned due to age and for purposes of standardization or because the burden of keeping them maintained is too great. What if you could turn these perfectly good though aging PCs into useful workstations for visitors or workers with relatively modest computing needs? There are many variations of how this could be useful; following are two scenarios that may be appealing.

Aging PC into a Thin-Client Machine

Imagine a company that has 20 PCs that are at the end of their useful Windows life, with the following specifications: 200MHz processor, 32MB of RAM, 2-4GB hard drives. They are constantly breaking down or needing software updates, and you're contemplating an upgrade to new hardware and the latest Windows operating system. The conventional solution is to buy 20 replacement PCs with Microsoft Windows at an average cost of $600-$800 or a total of $12,000-$16,000, and additional applications can quickly raise those figures.

An alternative Linux solution allows you to keep your existing PCs but to burn copies of the KNOPPIX CD, setting the PCs to boot from the CD. The total cost for materials for this solution is about $ .25 per PC, or $5 plus the time to complete the conversion. Then you can invest $2,000 in a file server that can save all the files and if necessary serve applications through a terminal server model, which can extend the useful life of the hardware for a number of years. This solution has limitations, but it does provide a couple of advantages. First, there are fewer moving parts at the user's desktop so there are fewer things that can break. Second, because the system is read-only users have significant protection from viruses as well as other undesirable changes that result from conventional PC configurations. Third, new applications can be pushed out to users from your central terminal server or via a Web services model that no longer requires changes on the client machine. For more information on thin-client computing, see my story in the January 2004 issue of LinuxWorld Magazine, "Desktop Linux: Think Thin" (Vol. 2, issue 1, www.linuxworld.com/story/38281.htm).

Kiosk for Web Browsing and Internet Access or Training Labs

There is an old saying, "One man's trash in another man's treasure." In the day and age when PCs are selling for less than $400, there is little incentive to keep old PCs in service and many organizations refresh their workstations often. Just because your workstations are being replaced doesn't mean you can't find new uses for your older PCs. One such use is to create kiosks for visitors to access the Web and check their e-mail when visiting your facility, or perhaps to outfit a training room that does Web-based training. These PCs, once configured to boot from CD, are impervious to most software failures. Since the file system on the PC is read-only, any problems can be fixed with a simple reboot. Because of this virtually bulletproof configuration, Linux distributions that run from a live file system CD lend themselves to a multi-user situation. Another alternative is to demonstrate this solution to a local charitable organization and donate the PCs to them - a local school will understand the value of the donation and potentially provide a tax write-off. Also, before you donate them you can use the SHRED utility mentioned later in this article to ensure that all data has been removed.

Traveling Desktop

Many people today have laptops, but it's not always convenient to carry one. Often when we visit friends they have a computer that we may borrow. These computers usually have an Internet connection and some core applications, but they don't usually have the data we need. One solution is to use KNOPPIX in conjunction with a USB memory stick. The memory stick can hold all your critical data, such as your address book and documents, and maybe a calendar or other information that you want to make sure travels with you. One way to accomplish this is to use the "persistent Knoppix home directory." To do this you can allow Knoppix to boot from your USB thumb drive and make your computing environment both lightweight and highly portable. The following recipe will give you a blueprint to accomplish this type of solution:

  1. Boot into Knoppix and insert your USB storage drive.
  2. Choose "Create a persistent KNOPPIX Home directory" by going to your K Menu > Configure.
  3. When asked if you want to create a persistent home directory, choose "Yes."
  4. Now you choose to create the partition on your USB key; usually these drives will register as /dev/sda or /dev/sda1.
  5. Next you will be offered the choice to use the ENTIRE Partition, if you are only using your USB thumb drive for Knoppix this should be fine. If you choose the FAT32 format you can access the thumb drive from both Linux and Windows.

Now you can take this CD and thumb drive to another computer and your data and settings will travel with you. Knoppix.net has a Persistent Home How-To on their Web site (www.knoppix.net/docs/index.php/PersistentHomeHowTo); their forums offer additional information for this type of configuration.

Rescue Utilities

There are tons of commercial solutions for reviving "dead" Windows PCs by numerous reputable software makers. However, the Knoppix live CD distribution includes utilities that can solve many common problems that these often-expensive solutions address.

Windows Installation Won't Boot

Sometimes Windows installations run into errors that won't boot. In these cases you have a couple of options; the first is to try your rescue disk from the operating system you have installed. If that doesn't work you can boot from your Knoppix disk to install files, edit configurations, and access your data. Sometimes it may be necessary for you to download a file and overwrite one that is corrupt so that your installation can still boot. You can use Knoppix to boot and edit your windows.sys or other system files that might prevent Windows from booting.

Rescuing Files and Moving Them to a Windows File Server

A couple of months ago a friend of mine brought me his laptop that was running Windows 98; no matter what he tried he could not get Windows to boot. After considerable time spent investigating his problem I was unable to boot Windows either. This was a huge problem for him as he had a presentation (for his son's wedding) held hostage by his laptop. I told him not to worry and pulled out my Knoppix CD. I then proceeded to successfully boot his four-year-old Gateway laptop via Knoppix. Since the presentation he needed was in PowerPoint I booted up in Windows PC and copied the files over from one PC to the other. I did this through the handy LinNeighborhood application (www.bnro.de/~schmidjo), a front end for Samba (www.samba.org) that allows Linux users to access Windows files and print services using the Server Message Block (SMB) protocol.

To solve my friend's dilemma I launched LinNeighborhood, which allowed me to browse the Windows PCs on my network. Then I entered my information for the machine I wanted to connect to (in this case it was called Hinkle-Top and I entered the IP address and the Hinkle-Top entry showed up in the LinNeighborhood window). Then I right-clicked the associated icon and chose to scan as user. The scan as user function allowed me to enter my Windows username and password. This then allowed me to see all the shared directories on that Windows PC. The next step was to right click on the share I wanted to access (in this case it was called Data) and choose mount. The directory then showed up in the lower window with the mount point (in this case /root/mnt/HINKLE-TOP/Data/); then since my friend needed to browse his drive I chose to set up Konqueror (a graphical file manager and Web browser like Windows explorer). To make sure I had full permissions to read and write to the partition I went to a command prompt and launched Konqueror by typing "su" to gain super user access, then I typed konqueror to run the graphical utility with the permissions I needed. To move the files I dragged them from one Window to another. Figure 1 shows both the local disk and the remote Windows PC. In conjunction with Konqueror file manager, this solution offers an easy way to drag and drop files from one PC to another.

Manipulating a Hard Drive (Formatting, Partitioning, Erasing)

Knoppix includes many disk utilities for manipulating hard drives, including partitioning tools and utilities to securely delete data from the hard drive before it is thrown out or repurposed. The following tools are well suited to these types of tasks.

QTParted

QTParted (http://qtparted.sourceforge.net) is a graphical clone of the popular disk utility Partition Magic. It's written using the QT toolkit and the command line tool "parted," hence the name. What it I find it useful for in my Windows to Linux migration is to resize Windows partitions so that I can install Linux in a dual boot setup (see Figure 2).

fdisk

Many Windows users will recognize the term fdisk, which is a menu-driven program for creation and manipulation of partition tables. Partitions are logical disks on a physical device. These logical disks can be formatted with a variety of file systems. Also, fdisk can create or delete partitions and rewrite the master boot record. To use fdisk from Knoppix just launch a command prompt and make sure to su to root, then to access your disk type fdisk /dev/hda where hda is the name of your hard drive (usually this will be /dev/hda but if you have two hard drives you may see it as /dev/hdb). For more information on how to use fdisk you can type m for help at the Command: prompt. Also, you may find it useful to read the fdisk manual by typing info fdisk at a command prompt. This will bring up extended data on the fdisk partition table manipulator (see Figure 3).

Securely Deleting Data from a PC

SHRED - (Click Here !) - When you delete files from your operating system what normally happens is that you are only deleting an entry in the index of files that tells where that data is stored. Though the data is no longer visible it still exists until new data overwrites the old data. An unscrupulous user could use utilities to recover this data since files that you thought were deleted may still exist on the hard drive. That's where a utility like SHRED comes in handy. SHRED actually overwrites that data with new data so that there is little chance of recovery. By default shred will overwrite your hard drive 25 times with data and greatly reduce the risk of old data being recovered. To "shred" a hard drive with Knoppix you would simply go to a command line and type:

shred -verbose /dev/hda

where /dev/hda is the name of the hard drive you want to shred or delete all data from. In cases where sensitive data is stored on PCs it's very important to delete this data completely before repurposing or disposing of PCs and shred would be a useful means to securely wipe this data whether this be for patient data in a doctor's office or a government office that has standards for secure destruction of computer data.

Various Bootable Linux CD Distributions

There are many customized live CD Linux distributions that are useful and specialized for different purposes. The following are a few examples of special-use live CD Linux distributions.

Damn Small Linux

Damn Small Linux (www.damnsmalllinux.org) is a bootable CD Linux distribution that can fit on a 50MB CD about the size of a business card that you can carry in your wallet. Damn Small Linux doesn't have as many applications as Knoppix but it does include some critical applications including a mail client, Web browser, spreadsheet program, PDF viewer, and more.

INSERT (INside SEcurity REscue Toolkit)

INSERT (www.inside-security.de/INSERT_en.html) is a small footprint bootable Linux system that like Damn Small Linux can fit on a business card sized CD. However, INSERT includes tools that would be most useful for repairing and diagnosing computer problems.

Morphix

Morphix (www.morphix.org) is a distribution that can be "morphed" into a bootable Linux CD with your specifications. So in the likelihood that you have specific requirements for your own bootable Linux distribution you can roll your own Live CD distribution with the aid of the Morphix TROM (Total Remastering of Morphix - www.morphix.org/trom) utility.

These are a few of the specialized bootable Linux distributions that I have used in the past. For a more comprehensive list you can visit www.knoppix.net/docs/index.php/KnoppixCustomizations.

Summary

I hope you find these tips valuable in your everyday computing life. All these solutions are useful to average IT users. Users with modest knowledge of Linux can execute every one of the solutions mentioned here; with a little research and creativity you can solve these and many other inconveniences. Best of all, these applications are unencumbered by licensing fees and can be freely obtained from the Internet. The fact that they are almost all developed under an open source licenses means that it's easy for other community members to improve upon software and redistribute their improvements. It also makes it possible for unrelated parties to continue the work of the previous parties should they decide to stop developing their solution. This type of model makes a lot of sense, especially when it enables the widest possible involvement of developers and companies globally.

More Stories By Mark R. Hinkle

Mark Hinkle is the Vice President of Community at Cloud.com. the maker of the open source cloud computing management software, CloudStack He also is along-time open source expert and advocate. He is a co-founder of both the Open Source Management Consortium and the Desktop Linux Consortium. He has served as Editor-in-Chief for both LinuxWorld Magazine and Enterprise Open Source Magazine. Hinkle is also the author of the book, "Windows to Linux Business Desktop Migration" (Thomson, 2006). His blog on open source, technology, and new media can be found at http://www.socializedsoftware.com.

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Most Recent Comments
Arnold L. Johnson 01/20/08 09:10:49 AM EST

Your article is right on the money. I so much enjoy not being tethered to a Microsoft machine. Many friends have older PC's with borrowed copies of MS windows on them and can not get upgrades. I try to interest them in live-CD Linux, they fear not being compatible with MS business software. A live-CD says "don't take my word on this, but look here". I am so impressed.