Posted by: Eric Siebert
Eric Siebert, Live CD, virtual machine, VMware
Live CDs are bootable CD/DVD images that contain an operating system that you can boot from to perform various tasks on a server. When you boot from a live CD, the operating system from the server does not load. Instead the live CD operating system loads, allowing you access to the server’s file system. There are hundreds of free live CD’s available that you can download and use, and they are particularly useful for troubleshooting or repairing a problem with a server.
Most of these live CDs use one of the many Linux distributions as there is no cost for using them and they are very compact. There are also some Windows versions that use a special version of Windows called Windows PE. While physical servers usually rely on a physical CD/DVD which must be burned and placed in the server’s CD/DVD-ROM drive, virtual machines can make use of ISO images which are image files that can be directly mounted to a VM’s CD-ROM.
Live CDs have a wide range of functionality. It’s handy to have a good selection of them available. So when would you want to use a live CD?
•When you have a server that has been infected with a virus or spyware. Booting from a live CD will allow you to run scanning utilities to remove the infection without the server being active.
• When you have a corrupt operating system that will not boot or that crashes while booting. Booting from a live CD will allow you to repair corrupted files or configuration files.
• When you’re installing an application that renders a system unusable. Booting from a live CD will allow you to disable or uninstall the application.
• When you’ve forgotten the administrator password to log in to your server. Booting from a live CD can allow you to crack or reset it.
Almost all live CD images are available as an ISO download which is ready to use on your virtual machines. You simply edit the settings for the virtual machine and select the CD/DVD-ROM drive and map it to either your client CD or a host data store where you can select the ISO file. It’s a good idea to have an ISO data store available to all your hosts that contains the ISO images so you can use them when needed.
As mentioned, there are many live CD images that you can download and use, so to get you started I’ve compiled a list of some of the best ones that will make a good addition to your ISO library.
• Ultimate Boot CD – A Swiss Army knife boot CD which has many diagnostic, hard disk and file system tools as well as antivirus and network tools.
• Ultimate Boot CD for Windows – A Windows version of the Ultimate Boot CD with a huge array of tools including many antivirus and antispyware, disk, file, security, password reset, network tools and much more.
• Knoppix – A Linux Live CD that contains many tools and utilities.
• Backtrack – A huge selection of security tools that you can use to scan for vulnerabilities of your VMs.
• Kaspersky Resce CD – A Live CD with anti-virus scanner to clean infected systems.
• Gnome Partition Editor – A hard disk partition utility that lets you do all sorts of things with disk partitions and is particularly useful for resizing existing partitions on your VM after you have increased the size with vmkfstools or the VMware Infrastructure Client.
• Ophcrack – A utility that will crack forgotten Windows passwords.
• System Rescue CD – A multi-purpose rescue CD that includes partition editors, file system utilities, password recovery and much more.
These are just a few of the live CDs available. If you would like to build your own live CD based on Windows PE check out the Bart PE website for more info. You can also check out the live CD list website for a huge list of available live CD’s.