Incremental is only files that have change in a given period, based on
date/time stamp of the file. Differential is only files that have changed based on file size and CRC
(checksum redundancy check) Full is complete backup of all data in a given folder, volume, or drive. Image is a complete re-installable copy of a hard drive or partition.
So you need to think about what you have that is of the
highest value, then of value, then
how much time it will take you to recover from a disaster.
Irreplaceable documents should be printed
and stored where the elements will have the least effect, safe deposit box, etc.
Hard to replace or time consuming documents should be stored on a
non-volatile media, CD or DVD is the best.
Now we get down to the everyday document, I will use a web page as an
example. You create a web page on your computer, then when it is complete and
looks the way you want it you upload it to your web site. Then you forget about
the original on your hard drive until you need to update or change the page on
the site. You go to look for the page but some how it has been overwritten,
misplaced, or deleted. Now this is annoying but is not catastrophic. A
daily backup would have put that document on some other media than your computer that
you use every day. You could go to your backup and pull the original or latest
page on to your computer do your changes and upload it.
What about your operating system drive and all the apps you have installed
over time, you don't want to reinstall all of those again if your hard drive
fails. There is a way to do this also.
Image or Clone copy of your Operating System drive.
You would want to keep at least two copies of the installation of your OS.
At this time you can not make a copy of the original install because you have
installed a lot of programs, deleted files, and so on. It is best to make a copy
directly after the setup and before installing any applications. Once the system
is up and running in a stable condition then I make my copy. The reason for
doing this (bear with me on this one) is if I install an application and it
crashes then I don't have to start all over with the OS install. Just put the
copy back on the system, then I can figure out what cause the system to fail
when I was installing the application, or call the publisher's support and have
them figure it out.
A good use for the second copy is after you get all your applications
installed lets say you inadvertently received a virus, it is causing all kinds
of problems with your system. Just put the second copy on your system, restore
any data that has changed from the time of the copy to now. You still need to
keep those cd's, serial number's, and programs you downloaded safe.
One advantage of doing a copy after install is that you don't have to reinstall
all of your applications. I have one application that every time it is installed
I have to go to the publisher and get a new license, this is cool, keeps someone
from pirating it, but it is a pain because it takes three working days to get the
new activation code. With an image when I blow up my system (happens to the best
believe me) all I do is put the copy back on, restore some data and I am up and
running, takes about thirty or forty minutes.
There are numerous programs to do the image of your hard drives, I
recommend either Norton's Ghost or Acronis True Image
. There are free programs out there, but as the old axiom goes: You Get What
You Pay For. Be aware that you will need a bootable floppy or CD. Be sure to
read all the instructions before you start, printing the main points is a good
idea.
