Billix: a Sysadmin's Swiss Army Knife
A few things can go wrong when converting a USB key to run Billix (or any USB-based distribution). The most common issue is for the USB drive to fail to boot the system. This can be due to several things. Older systems often split USB disk support into USB-Floppy emulation and USB-HDD emulation. For Billix to work on these systems, USB-HDD needs to be enabled. If your drive came with the U3 Windows-based software vault, this typically needs to be disabled or removed prior to installing Billix.
If you're seeing “MBR123” or something similar in the upper-left corner, but the system is hanging, you have a misconfigured MBR. Try install-mbr again, and make sure to use the -p1 switch. You will need to run syslinux again after running install-mbr. If all else fails, you probably need to wipe the USB drive and begin again. Back up the data on the USB drive, then use fdisk to build a new partition table (make sure to set it as FAT or FAT32). Use mkfs.vfat (with the -F 32 switch if it's a FAT32 filesystem) to build a new blank filesystem, untar the tarball again, and run install-mbr and syslinux on the newly defined filesystem.
Damn Small Linux is a miniature version of Knoppix (it actually has much of the automatic hardware-detection routines of Knoppix in it). As such, it makes an excellent rescue environment, or it can be used as a quick “trusted desktop” in the event you need to “borrow” a friend's computer to do something. I have used DSL in the past to commandeer a system temporarily at a cybercafé, so I could log in to work and fix a sick server. I've even used DSL to boot and mount a corrupted Windows filesystem, and I was able to save some of the data. DSL is fairly full-featured for its size, and it comes with two window managers (JWM or Fluxbox). It can be configured to save its data back to the USB disk in a persistent fashion, so you always can be sure you have your critical files with you and that it's easily accessible.
All the Linux distribution installations have one thing in common: they are all network-based installs. Although this is a good thing for Billix, as they take up very little space (around 10MB for each distro), it can be a bad thing during installation as the installation time will vary with the speed of your Internet connection. There is one other upside to a network-based installation. In many cases, there is no need to update the newly installed operating system after installation, because the OS bits that are downloaded are typically up to date. Note that when using the Red Hat-based installers (CentOS 4.6, CentOS 5.1 and Fedora 8), the system may appear to hang during the download of a file called minstg2.img. The system probably isn't hanging; it's just downloading that file, which is fairly large (around 40MB), so it can take a while depending on the speed of the mirror and the speed of your connection. Take care not to specify the USB disk accidentally at the install target for the distribution you are attempting to install.
The memtest86 utility has been around for quite a few years, yet it's a key tool for a sysadmin when faced with a flaky computer. It does only one thing, but it does it very well: it tests the RAM of a system very thoroughly. Simply boot off the USB drive, select memtest from the menu, and press Enter, and memtest86 will load and begin testing the RAM of the system immediately. At this point, you can remove the USB drive from the computer. It's no longer needed as memtest86 is very small and loads completely into memory on startup.
The ntpwd Windows password “cracking” tool can be a controversial tool, but it is included in the Billix distribution because as a system administrator, I've been asked countless times to get into Windows systems (or accounts on Windows systems) where the password has been lost or forgotten. The ntpwd utility can be a bit daunting, as the UI is text-based and nearly nonexistent, but it does a good job of mounting FAT32- or NTFS-based partitions, editing the SAM account database and saving those changes. Be sure to read all the messages that ntpwd displays, and take care to select the proper disk partition to edit. Also, take the program's advice and nullify a password rather than trying to change it from within the interface—zeroing the password works much more reliably.
DBAN (otherwise known as Darik's Boot and Nuke) is a very good “nuke it from orbit” hard disk wiper. It provides various levels of wipe, from a basic “overwrite the disk with zeros” to a full DoD-certified, multipass wipe. Like memtest86, DBAN is small and loads completely into memory, so you can boot the utility, remove the USB drive, start a wipe and move on to another system. I've used to this to wipe clean disks on systems before handing them over to a recycler or before selling a system.
Bill Childers is the Virtual Editor for Linux Journal. No one really knows what that means.
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