Rescuing Linux Systems--Generic and Distribution-Specific Safety Nets - page 10
Sending Out an SOS
As mentioned in the introduction to this article, few things are more frustrating than being inches away from data that you can't access because of disk, boot loader, or filesystem problems or corruption. Having bootable floppies or CDs handy gives you a toolkit that you can use to bring a damaged Linux system back to life or to at least back up some or all of its data before resorting to the classic reformat/reinstall paradigm that is so popular in the Windows world.
As discussed in this article, having the installation CDs for the Linux distribution you are using is the fastest and easiest way to recover a damaged Linux system. Nowadays, all of the popular Linux distributions either provide an explicit rescue mode or a shell that you can use to try to repair filesystem damage, replace or reinstall missing or damaged files and packages, or reinstall your favorite bootloader.
If you are running many different types of Linux systems or simply can't find the installation disks used to build a damaged Linux system, the system-independent rescue disks discussed in this article can repair most common filesystem and bootloader-related problems. This article highlighted my personal favorites - there are many others. You can find an extensive list of pre-made rescue disks at http://www.tldp.org/HOWTO/Bootdisk-HOWTO/premade.html, which is a section of the Linux Boot Disk HOWTO which is itself an incredibly useful reference for resolving boot problems.
One of the greatest things about Linux is its community philosophy,
which is much of the reason for the system-independent rescue disks
discussed in this article. The greatest Unix recovery story I've ever
read was in a heroic old Usenet posting, now available thanks to
http://groups.google.com/groups?q=Mario+Wolczko+Alasdair&hl=en&lr=&ie=UTF-8&selm=telecom16.402.11%40massis.lcs.mit.edu&rnum=3. With a few Linux rescue disks in your sysadmin toolbox, you may be able to get the same results--your data or your system back--with much less wizardry.