| Disk Imaging (Ghost) Software |
| Written by Jenny Flex | |
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The term comes from one of the best commercial programs on the market to perform this task, a tool now sold by Symantec Corporation, Norton Ghost. As with many other categories of software, there a several tools available to perform this hard disk duplication, but Norton Ghost is still considered the “top dog” by many. Some other people refer to the process as disk imaging, as we will for the rest of this article. So what happens when you create a disk image? You create, in essence, a complete copy of a hard disk. This copies all of the data on the hard disk at the time the image is made. This hard disk can be so complete that it incorporates all of the software on the hard disk that performs such mundane and technical tasks as making the CD drive work, for example (called device driver software). Using this disk image you can re-create the contents of the hard disk that is in the image to another location, typically another hard disk. This can be one of the simplest methods of disaster recovery.The disk image is typically created using some software program. The program usually works by allowing the user to set certain options to control the disk image, and then sets to creating the image. For utmost safety, the image is usually stored to a place other than the hard disk that is being imaged. The structure of the source hard disk is copied to the new location, per the options that the user set. After some period of time has passed (larger disks will take longer than smaller disks) the image is complete. The software program that created the image often has the ability to make a bootable disk to allow you to re-start a computer that will not start using its hard drive. This bootable disk then often contains a sub-set of the imaging program that can be used to restore the image of the original hard drive. And, there you have it, a restored hard drive that will work just as it did. Now, bear in mind, that there are some limitations on using disk imaging software. For starters, you are making an exact duplicate of the hard disk. If you use options for including device drivers and you put the image on a different computer with different hardware than the original computer used to make the image, then things may not work as expected. You may have a device driver software trying to control a different device! Another potential drawback to using imaging software could be if you create an image of a computer system that has a virus. If you haven’t removed the virus from the original system, then the virus will be copied to the disk image. Of course, when that image is used to restore a disk, the virus will be restored right along with the data. You should be sure that the source system is clean of viruses and that it is working correctly prior to making the disk image. As good as disk imaging sounds, it has some drawbacks when compared to typical data backup and restore. For starters, when using disk imaging you are making an image of the entire hard disk, every time. This, of course, can be a lengthy process and may not be practical as a regular practice. You’ll also need to make sure that you have enough storage media to hold the disk image. Disk image software may result in data storage needs that could far exceed what you would use in a backup situation using differential or incremental backup strategies. This, of course, will depend heavily on the actual software you use for making your image. Higher end software (such as Norton Ghost) will have more and better options than cheaper, lower end, software. When you restore from a backup, you may be able to more easily select files to restore than may be the case if you use imaging software. Again, this will depend on the software you are actually using. Using imaging software can be a powerful tool to quickly restore an image of a hard disk, especially in cases where you need to quickly bring up a hard disk or portions of a hard disk and a good backup is not available. While not a totally foolproof solution for computer disaster recovery, it has a place in the overall disaster recovery software toolbox. |
Can a ghost actually help you with your disaster recovery software? Are we talking about the wandering and tormented spirits of long-deleted files? Of course not. What we are talking about is a category of software that is an important component of disaster recovery and should be in the toolbox alongside of data backup and restore, and file recovery software. To “ghost” a computer means to make a perfect copy of a computer hard disk as it exists at a given point in time. | < Prev | Next > |
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