Listening to the heads on your hard disk clicking when the disk fails is bad enough as it is, but worse things are still to come. Although buying and installing a replacement disk is unlikely to faze most users, this is just the start of a time-consuming installation marathon that can easily take a day or two to restore the whole system with your personal preferences and favorite wallpaper. Having a backup copy of the whole disk means that you can carry on with your work after about an hour, just as if nothing had gone wrong.

Preservatives

Retailers offer a variety of programs that will create a full backup with the press of a button, but these programs cost money. The open source Clonezilla [1] is an alternative to proprietary tools such as True Image, Drive Image, and Norton Ghost. Clonezilla will read a partition or your whole disk bit by bit and store the results in a (fairly large) file known as an image or write directly to a second medium. This allows you to clone a disk fairly quickly, which is handy if you are moving to a new computer and want to take your old system with you.

Clonezilla comes in two flavors: Clonezilla Live, which boots from a CD; or a bootable USB stick, which backs up a partition on another medium attached to your computer and is your best choice for everyday work. If needed, Clonezilla Live will back images up to the network, for example an NFS, SSH, or Samba server. This is really useful on home or school networks where you could store drive images on a small NAS. Clonezilla Server Edition can even clone the disks in multiple computers simultaneously over a network, but it requires a special environment to do so (see the "Clonezilla SE" box).

Drive Fodder

To back up your own disk, go to the Clonezilla project homepage and pick up the latest stable version from the Download area. If you prefer to boot Clonezilla Live from a CD, grab the ISO file and then burn a CD with the image. If you prefer the USB stick approach, download the ZIP archive and then make sure the USB stick has a FAT32-formatted partition. Next, mount the partition, unpack the Clonezilla ZIP archive on it, pop up a terminal window and change to the utils/linux subdirectory, and then give the bash makeboot.sh /dev/sdb1 command to make the stick bootable (replace sbd1 with the device name for the partition on the stick).

There is a good reason for not being able to run Clonezilla like any other program on the active Linux system. To be able to clone a partition without any risk, you must dismount the partition. If this is not the case, Linux might write to the disk while you are backing up your data, and thus ruin the image. Unmounting the system partition is not easy; thus, the only alternative is to boot Clonezilla from an external medium. If you succeed in doing so, you will see the screen shown in Figure 1.

Figure 1: The Clonezilla Live CD welcome screen.

Clonezilla Live boots automatically, unless you press a key. If you experience graphics problems later on, you may need to select a lower resolution, or even Safe graphic settings. In case of other hardware problems, you can still try Failsafe mode. The To RAM item copies the whole Clonezilla Live system into main memory. You can then remove the CD or unplug the USB stick. This is really useful if you only have a single free USB port, as is the case with some netbooks. Use the arrow keys to select an option, and press Enter to execute the selected action.

Wizards

Whatever you select, you will be running a Debian Live System that initially fires a number of text messages at you. The next step is to select a language; English is the default.

Figure 2: Selecting a language in Clonezilla; support for some Asian languages is available.

You can now launch Clonezilla or switch to the command line. When you launch Clonezilla, it will prompt you to choose whether to drop the partition into an image file (device-image) or write directly to another, physical hard disk (that is, clone the partition – device-device). If you are backing up an existing Linux system, the image file is easier to archive and the first of these options is your best bet (Figure 3).

Figure 3: Choosing between an image or a direct copy.