Respected nerds, techs, geeks and dear fellow members

I am having presently one hard disk drive seagate of 80 GB...

I am about to buy a hard disk tommorow....

In this contect can anyone plz clarify my following doubts...

A. I have heard that we can set up two HDD with RAID connection for striping and mirroring (I dont know what these means)...

((a)) Do i need to buy the second hard disk also of size 80 GB so that i can set up RAID connection with my previous hard disk of 80 GB...???

Or is it that i can purchase 200 GB (say) of HDD tommorow and with my previous 80 GB...I can still set up RAID Connection...????????

I mean is it mandatory that both HDDs be of same size for setting up RAID connection...????

() Also to set up RAID connection is it necessary that both hard disk should be from same company....?????

Or can i have say one seagate HDD set up with say another samsung HDD in RAID...?????

(©) Can we have three hard disk drives and still set RAID connection....????

Or is it only restricted to two HDD...????

() what exactly is RAID connection and what benefits it offers....?????????

((e)) Can i still create drive image of my hard disk after setting up RAID connection......????????????????

Now as my computer and technical knowledge is very very limited (as i am a hardcore finance guy), my best and only recourse are wonderful forums like the one where i am posting right now. Its really great to have advice and suggestion of knowledgeable people here who do not have any self interest and are very helping in nature. So again I am daring to ask a few queries (infact more than few) and again hope that u people will really really help me out as u have always helped me in the past.

Thanks from deepest core of my heart for taking so much time effort and patience in READING and possibly replying...Its truly really and geniuenly appreciated....

And yes if anyone would like to add anything or say something else or suggest something better which i may be missing plz feel free to do so...

best regards

sunando

sunandoghosh at rediffmail dot com

You are looking for a lot of information. Rather than try to post that all here have a look at AC&NC's descriptions of Raid levels and determine what level you want. Next you need to determine if your computer can support the level (or indeed any level) of Raid. What type of Motherboard (make and model number) do you have? CPU? RAM? IDE only or also SATA? Operating system?

By the way, putting urgent attention in the topic title is generally self-defeating. Everyone who comes here gets the same attention and asking for special attention will more often than not get you ignored. Everyone volunteers their time here and posts when they can. We all have lives beyond this forum and tend to those first of all. If you need help that urgently you may have to go to a computer store and pay for it.