Emergency Response

Bootstrapping with Grml

The extras in Grml are almost as useful as the basic feature set. The fully automatic installation (FAI) is a Debian-specific bootstrapping system for bare metal deployment. A running Grml instance can become a complete FAI setup, as required. The grml-live tool, from the team led by Michael Prokop, builds on the FAI function and serves as the base for Debian-based Live distributions.

The Grml-Live framework makes remastering Grml CDs easier. Anyone needing a locally modified Grml version for specific hardware or kernel packages will be able to achieve their goal quickly using Grml-Live. Grml mainly comprises packages that users can find in the official Debian archive. Debian's cornucopia is available if you want to build a local Grml variant. For example, you can easily build a Grml image with a newer kernel. Anyone who needs special modules can load them, either in the form of a Debian package into the Grml run time or integrated into a local Grml image.

Grml is a jack of all trades that, if necessary, acts as a terminal server and distributes Grml to all other computers on the network via PXE. Instructions for various topics related to Grml can be found on the Grml wiki [4]. Prokop has remained true to form: the Grml website does not provide information regarding how to install Grml on a disk.

Because Grml is not intended to be an everyday desktop system, anyone who wants to go that way should, according to Prokop, use a real Debian system. Then, you typically only have to deal with ironic release name that Prokop assigned to Grml: Version 2014.11 was current at the time the magazine went to press and bore the name "Gschistigschasti," which means "clutter" in the Austrian flavor of German.

SystemRescueCd: Back to the Roots

SystemRescueCd [5] is an appropriate name for the next project; it is a succinct description of the tasks its authors supply on a Live CD or USB stick. Thematically, SystemRescueCd is more in line with Grml than Knoppix. The content of the image, at about 430MB, is limited to the essentials. SystemRescueCd does not aim to be a Live desktop system; rather, it is specifically a system for dealing with emergencies. The diversity provided by the solution is exciting.

The CD boot screen (Figure 3) shows that SystemRescueCd pays attention to more the Linux universe. Anyone who needs a DOS environment for updating firmware on a server device using Stone Age tools can simply boot to FreeDOS. The memtest86 memory-testing software is also an option.

Figure 3: SystemRescueCd boots Linux in the default configuration, but FreeDOS and MemTest86 are also options.

SystemRescueCd is based on the Gentoo Linux distribution and contains an X11 environment that includes Firefox and a number of graphical tools that add to the appeal of SystemRescueCd. The graphical user interface can be also switched off. Changes to the partition tables, such as reinstalling GRUB or checking hard drives, work directly from the booted system.

Filesystem backups are no problem either – users may even choose whether they would prefer to export the images to a connected storage device, burn them to an optical medium, or store them via the network. If you want to know whether your hard drive is still sane, you will appreciate the TestDisk tool.

Better Desktop than Server

SystemRescueCd seems to be aimed more at desktop users than at server administrators, in that it uses kernel 3.14, which is no longer quite up to date. Common desktop controllers typically still work well with older versions of the kernel, but that's not always the case with new storage controllers on servers. However, SystemRescueCd boasts basic server features; for example, it understands LVM very well.

One nifty feature is the ability to build your own SystemRescueCd [6]. Knowledge in dealing with Gentoo is useful, because additional software is installed using the Emerge tool, the command-line interface to the Gentoo Portage package management system.