Symantec NORTON GHOST, User Manual

Page: 39 / 80

Managing image files
39
Managing image files
Norton Ghost can create an image file that contains all the information
required to recreate a complete disk or partition. Image files are a useful
way to store and reliably compress images of model system configurations,
or to create backup copies of complete drives or partitions.
The image files created with Norton Ghost have a .gho extension by
default. They can contain the entire disk or partitions in the disk. Image
files support:
■
Various levels of compression
■
CRC32 data integrity checking
■
Splitting of media files
■
Spanning across volumes
If you also use the Ghost Explorer application, an image file companion
utility, individual files from these image files can be recovered selectively
without having to restore the complete partition or disk.
Image files and compression
Image files created in Norton Ghost support several levels of data
compression. When using Norton Ghost in interactive mode, three
compression options are provided: none, fast, and high. The Norton Ghost
command-line switches provide access to nine levels of compression. The
compression switch -Z is detailed in Appendix A.
As a general rule, the more compression you use, the slower Norton Ghost
will operate. However, compression can improve speed when there is a
data transfer bottleneck. There is a big difference in speed between high
compression and no compression when creating an image file on a local
disk. Over a NetBIOS connection, fast compression is often as fast as, or
faster than, no compression. Over a parallel cable, high compression is
often faster than no compression because fewer bytes need to be sent over
the cable. Decompression of high-compressed images is much faster than
the original compression. The level of compression you should select
depends on your own individual requirements.