Introduction to Knoppix

Kyle Rankin

Author of Knoppix Hacks

What is Knoppix?

A complete Linux distribution that runs directly from a bootable CD-ROM, Knoppix has many uses:

• Demonstrate Linux to newcomers
• Portable Linux Distribution
• Make Linux easier to install
• Tools for system administration
• Rescue disc (for Linux and Windows)
• Make your own live CD
• Many other uses

Demonstrate Linux

Why Knoppix is great for demos:

• No need to install
• Fast
• Great hardware autodetection
• Includes lots of software
• Non-intrusive

Portable Linux Distribution

Take your distro with you:

• Cheat Codes (run anywhere)
• Persistent Settings
• saveconfig
• mkpersistenthome

Cheat Codes

Cheat codes let you tweak boot behavior

• Change screen resolution settings
• Change desktops
• Change kernels
• Bypass mistakes in hardware detection
• Free up the CD-ROM
• Expert and others

Persistent Settings

/usr/sbin/saveconfig

• saveconfig can save a number of settings
• Desktop
• home directory "dotfiles"
• network and display settings
• printers and other settings in /etc
• Doesn't auto-update
• "myconf=scan" restores settings
• Tweak without remastering

Persistent Settings

mkpersistenthome

• Creates a filesystem image of /home
• usb key/floppy drive
• hard drive partition
• Always current settings
• "home=scan" restores settings

Knoppix the Linux installer

• Copies full CD to disk (requires 2GB)
• GUI and text-based
• Knoppix 3.4 and greater has 3 installation types:
• Debian
• Knoppix
• Beginner
• Not exactly pure Debian

Knoppix the Admin Toolbox

• Backup filesystems
• Image disks
• Emergency services
• Apache
• Samba
• NFS, FTP, MySQL, BIND, etc
• Forensics

Knoppix the Rescue Disk

• Excellent hardware detection
• Safe for the underlying system
• Comes with useful rescue tools: lilo, grub, dd, gpart, dpkg, rpm, etc.
• Full Internet access for troubleshooting
• Games!Productivity Applications

The Windows "Recovery" Disk

• Included on Windows 2000 and XP install disks
• Has predefined functions to repair a broken Windows system.

The Windows "Recovery" Disk

Knoppix the Windows Recovery Disk

What Knoppix can do

• Write to the full disk (even NTFS)
• Fix boot.ini
• Scan for viruses
• Install files from .cabs
• Blank passwords
• Edit the registry

Make Your Own Live CD

1. Check other Knoppix derivatives
2. Copy Knoppix structure to a hard drive
3. chroot
4. Make changes
5. Recreate compressed filesystem
6. Recreate .iso
7. Test with bootfrom
8. Burn to CD

Fix Catastrophic Screw-ups

What are catastrophic screw-ups?

• root@ttyp0[/]# rm -rf .
• C:\ fdisk /mbr (or installing Windows)
• root@ttyp0[/]# dd if=/lib/grub/i386-pc/stage1 of=/dev/hda bs=512 count=1

Death-(well MBR-)defying Live Demo!

Delete the complete Master Boot Record and restore it and grub using Knoppix

I Like My Laptop

• Fujitsu P2110 (867Mhz Crusoe, portable, 10.6" 16:9 display, excellent battery life)
• Dual-boots Debian (95%) and Windows 2000 (5%)
• New 5400RPM 16MB cache hard drive
• Lots of custom scripts and tweaks (http://greenfly.org/fujitsu)

How to Erase Your MBR

root@ttyp0[/]# dd if=/dev/zero of=/dev/hda bs=512 count=1

Boot Knoppix

Use console mode (boot with knoppix 2)

Not necessary, but saves time since all the recovery tools are command line based

Gpart

• short for "Guess Partition"
• scans a drive for anything that looks like the beginning and end of a partition, then creates a MBR based on it
• works best with primary partitions
• not perfect (double check results)

Run Gpart

First run gpart without the -W option to test

• root@ttyp0[/]# gpart /dev/hda

Then use -W to actually write the changes

• root@ttyp0[/]# gpart -W /dev/hda /dev/hda

Tweak the Results

gpart might not correctly find the end of all of your partitions.

Use a tool like fdisk or cfdisk to recreate the partition to fill up its space in this case.

Fix Grub

• Mount the Linux partition that contains your /boot directory read-write:
root@ttyp0[/]# mount -o rw /dev/hda3 /mnt/hda3
• Run grub-install to restore grub to the boot sector:
root@ttyp0[/]# grub-install --root-directory=/mnt/hda3 /dev/hda
• Reboot

Other Resources

• Official Knoppix Website:
http://www.knoppix.org
• Unofficial Knoppix Forum (English):
http://www.knoppix.net
• My Book!
http://www.oreilly.com/catalog/knoppixhks/