Open Source

Build a recovery floppy for your Linux system with tomsrtbt

What do you do when your Linux system won't boot? Panic? Weep? Start sending out resumes? If you have a boot floppy, you can use it to restart your system and figure out what's wrong.

From the time IBM shipped the first PC right up until Windows 2000, one of the nice things about it was that when you ran into a problem with a hard drive, all you had to do was get out your trusty DOS boot disk and boot the system. From there, you could access the hard drive and recover data or repair the problem. Even now when a single DOS disk won’t do the trick, you can still build a set of recovery disks for Windows 2000 and XP. Now, with Toms Root Boot (tomsrtbt), you can do the same for your Linux workstations and servers.Tomsrtbt, developed by Tom Oehser, provides an easy method for creating a recovery/rescue disk for your Linux system.

Installing tomsrtbt
Tomsrtbt gives you several options for installation. You can create repair disks or boot CDs, and you can even create them under either Linux or from DOS. You’ll need to download the following different packages:
  • tomsrtbt-2.0.103.tar.gz: To create a boot floppy from Linux
  • tomsrtbt-2.0.103.ElTorito.288.img.bz2: To create a boot CD from Linux
  • To create a Linux boot floppy from a DOS session under DOS or Windows

To build a floppy disk under Linux, open a command prompt and use the su command to change to the root user. Unpack the archive with the command tar -zxvf tomsrtbt-2.0.103.tar.gz. Change into the tomsrtbt-2.0.103 directory. Finally, run:

To create a bootable CD-ROM,extract the root boot files from the tomsrtbt-2.0.103.ElTorito.288.img.bz2archive by typingbunzip2 tomsrtbt-2.0.103.ElTorito.288.img.bz2.Create a separate directory to hold the image file by typing mkdir toms-image. Next, create a separate subdirectory under toms-image to hold any additional files you want to include in the ISO image by typing mkdir /toms-image/utilities.

Copy any additional files you want on the CD to the add-on directory. You have at least 650 MB to use on the CD, so just about any collection of files may be added to the ISO image. Create the ISO image from the downloaded image, and include any additional tools or utilities with this command:
mkisofs -b /tomsimage/tomsrtbt-2.1.103.ElTorito.img -c boot.catalog -o tomsrtbt.iso utilities

Once the ISO image is created, burn it to the CD with any Windows or Linux CD recording software. To use the Linux cdrecord utility, first get the device numbers for your CD writer by running the following command as root:
cdrecord –scanbus

When the device numbers are known, use the cdrecord command to burn the ISO image:
cdrecord dev=0,0,0 -v -eject -speed=12 tomsrtbt.iso

Once the boot disk is created, reboot the machine. The computer is now running a stand-alone Linux distribution capable of system rescue and recovery.

To perform the installation under DOS on a DOS or Windows machine, unzip into a temporary directory on your computer. Run the install program from the tomsrtbt-2.0.103.dos directory.

Adding additional tools and utilities
There are no restrictions on what tools you may add to the CD-ROM or the floppy other than the limitations applied by the media. In addition to this list, any script, tool, or utility may be added to the floppy or CD-ROM. The available add-on packages include drivers for network interfaces, PCMCIA utilities, and additional support for the kernel.

Configuring a static IP address
When the system boots, tomsrtbt will look for a DHCP server, and if none is found, an IP address of will be configured for the network interface. To supply the network interface for another IP address, in this case with a netmask of and a default gateway of, use the following commands:
ifconfig eth0
route add default eth0
route add default gw

Configuring SAMBA
To configure SAMBA access, first download the following add-ons for tomsrtbt:

Once the files have been downloaded, run the following series of commands:
bunzip2 smb*.bz2

Create symbolic links to the binaries using these commands:
insmod ./smbfs.o
ln -s ./smbmount /usr/bin/smbmount
ln -s ./smbumount /usr/bin/smbumount
ln -s ./smbmnt /usr/bin/smbmnt

Then, create the mount point for SAMBA like this:
mkdir /mnt/smb

Finally, create a SAMBA share named linux on a Windows PC with the IP address In this example, smbmount will not ask for a password. This step will look like this:
smbmount // /smb -o guest

That's it!
All systems need some way to recover from disasters. Tomsrtbt provides an easy way to create a rescue and recovery disk for your system, in addition to a good set of utilities for configuring almost all aspects of the operating environment.

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