David, what a great explanation. I appreciate the detail, it really help me understand the difference between backups and imaging.

One question still remains, is an image 'smaller' in size than the information it 'snap a shot' of (i.e. is an image COMPRESSED
information)?

TIA
Vic
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"David H. Lipman" wrote in message ...
Disk imaging is the process where the admin. runs software, outside of the Operating System
like booting DOS from a Floppy Disk, and creates an image of the entire hard disk. It is a
"snap shot" of the system at the point the system was imaged. The image could be a series
of disk files, stored on a Tape Drive, CD disks, DVD media, ZIP disks, etc. Using software
files can be extracted individually or enmasse from the image.

Using the software an image can be made and restored to a hard disk that isn't even
formatted. For example, lets say that an OS is running with a 20GB hard disk that has 1GB
free. An image can be made, a 60GB hard disk can be installed and the image restored to the
empty hard disk. Now you have the exact same system not with 1GB free hard disk space but a
system with 41GB free disk space.

Another example might be I have 10 identical model platforms. Lets say an IBM Thinkpad
A22m. I can install all the software on one of the notebooks. Completely configure all the
software. Depending on the OS, SysPrep the platform. Then an image can be created. Now
that image can be restored to the other nine platforms. Note this *only* works with
identical model platforms. When done, 10 systems will be setup exactly alike.

Two well know imaging packages are Norton/Symantec Ghost and Acronis True Image.

Imaging is more exact that backups. Backups are usually selected data but can be an entire
system. However, a backup will only copy data files on a hard disk. It will not create a
representation of the hard disk's partition table or file system. In the example above, if
an image is made of a Win2K platform using NTFS, the image can be restored to an bare hard
disk and the final object will be Win2K on NTFS. Another difference is that the backup
software usually runs under the OS. When this is done, programs and the Operating System
will hold File Handles open. This can be a hindrance to both backing those files up and
restoring them. This can be overcome by using a backup application that can be executed
outside the OS like off a floppy disk. However, to restore the files to a hard disk,. the
hard disk must be High Level Formatted.

HTH

--
Dave




"Vic" wrote in message
...
| Was going through posts in this group and saw a number of comments on 'disk imaging'. I've
heard of 'imaging' from years back but
| never understood what it is, or how someone can take an 'image' and restore all their data
from an image to another drive. To me
| imaging sounds like backing-up information, yet a disk image sounds very small in size
compared to a backup.
|
| Would is the difference between imaging and backing-up?
| What is 'imaging'?
|
| Thanks,
| Vic
|
|