Hi, as anybody would agree, installing Gentoo is pain although its a good learning experience.

But what do we do if for some reason the harddisk is wiped out and we need to install it from the beginning? With other distros its as easy as installing from current cd iso image and then updating the system (with tools like apt-get update-upgrade or yum update...).

With this in mind I would like to know if there is a method to capture our harddisk install and later use (or install(?) ) it as and when required?

Sorry, if its a dumb question but I don't know how to do it; even could not find a good phrase so as to google.

I disagree
To install Gentoo is no more "pain" than to install another distro (IMO) - aside from the amount of time it takes to get all the compiling done - which depends on how powerful your machine is.

The process of capturing the contents of the harddisk would be the same as with every other distribution.
I use rsync to do that - and put the archive on a DVD or another harddrive.

There are other ways which might suit your needs better.
(specialised tools, or just tar and any compression tool, or cp, or dd (rather not this one though...)
The Gentoo Live-CD, which you already have, can be used to reinstall the previously captured contents.

HTH

Some people like what they call stage4/stage5 backup.

In gentoo, stages are pre-packaged systems which are numbered depending on how close to a final working OS they are. While the number grows the "generic" nature of the stages diminishes. In ancient times, people used to use stage1 to install gentoo. A stage1 was nothing but a very basic system with a very basic toolchain. So you have to first, bootstrap it to get a working full toolchain, then start compiling the basic system tools. A stage2 was a bootstrapped stage1. A stage3 has the basic system and a fully working toolchain (and it's the only supported method of installation today). Nowadays, stage1 and 2 are not used by the big public, and are meant only for gentoo developers.

In addition to these, some gentoo users created the concept of what they call stage4 and stage5, which are basically fully working systems tailored to their needs, meant to restore the system easily and on a quick way if something bad happens. There's some info about stage4 and stage5 in the gentoo forum, like for example this one:

http://forums.gentoo.org/viewtopic-t-534039.html

However, being as simple natured as I am, I usually just use tar like I'd do on any other linux OS. Simple, easy and portable solution.

PS. I never tried stage4/5 at all.

In fact, the Stage 5 will do the job for sure :P

Ya, that stage5 script was written by you Read the link posted by i92guboj. Will follow.

Great :P