What do you do when your system doesn't boot? If you happen to have disks provided by a distribution vendor, then you can probably boot from them; however, you can often only use them to reinstall the operating system, not repair your system.
What do you do when your system doesn’t boot? If you happen to have disks provided by a distribution vendor, then you can probably boot from them; however, you can often only use them to reinstall the operating system, not repair your system.
What you need is a bootable rescue disk that contains tools you can use to diagnose what’s wrong with your system and fix it. If the rescue disk is a floppy (with a capacity of 1.44 MB) rather than a CD-ROM, it can be very challenging to cram all the tools you want on it.
Since inexpensive CD-ROM burners have become widely available, it’s possible to build a bootable CD-ROM full of tools. This month’s project lets you do exactly that.
Back in 1999, when Linux and the IPO market were booming, some of the folks at Linuxcare had a great idea: a “Bootable Business Card” (BBC). They used a CD-ROM in the dimensions of a business card (able to hold about 50 MB) and placed a miniature Linux distribution on it.
They had two goals in mind: put as many useful system recovery and networking tools on the CD as possible and put their brand name on it so that folks would remember Linuxcare. The project was incredibly successful at both. Linuxcare gave away over 10,000 BBCs. Demand for them was so high that Linuxcare made ISO images available for download on its Web site so that folks could grab a copy and burn their own CD-ROM.
The original developers eventually left Linuxcare and went on to form their own project called the LNX-BBC (http://www.lnx-bbc.org).
|Figure One: The Bootable Business Card login prompt.|
After downloading the ISO image from the LNX-BBC site, you can burn it to a CD-R or CD-RW using cdrecord or your favorite CD burning software.
Once you’ve got the CD burned, make sure your computer’s BIOS is configured to enable booting from CD, insert the CD, and reboot. During the boot process, the BBC will scan your system and attempt to mount any filesystems it recognizes. The login prompt will tell you what the assigned root password is (see Figure One).
You’ll find all the usual recovery tools: fsck, fdisk, lilo, and so on. However, one of the coolest features of the BBC is the trivial-net-setup program that configures the networking on your system after asking you a few simple questions. Once networking is up, you can run all the networking tools you’d expect: ssh, traceroute, tcpdump, and many more.
In addition to all the networking and recovery tools that are included, the BBC contains a full set of modules for the kernel, PCMCIA tools, XFree86, xterm, and even a full installation of Perl. With all that software available, the BBC can be used for more than just rescuing a crashed system. For example, you could use it to setup a temporary firewall or router, packet sniffer, or networked workstation.
Making Your Own
Like any good Open Source project, the complete build environment for the BBC is documented (available via CVS) and there’s a mailing list dedicated to the project. Having easy access to the “source code” means that you can build custom BBCs for your own use. And if you’re using a full-sized (650 MB) CD-ROM rather than the BBC form factor, you have the room you need to build a fully-working Linux installation with all the bells and whistles (Emacs, Netscape, KDE, etc.) you could possibly want.
The BBC packs a lot of functionality into a very small and easy-to-use package. You should take a few minutes and try it out before you actually find yourself wishing that you had a rescue disk handy.
Have an idea for a project we should feature? Drop a note to email@example.com and let us know.