HDD - RAID - multiple issues - urgent attention

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...?????

((c)) 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

 

IMO the best use of RAID is mirrored because you automatically back all your stuff up in case one of the drives fails ... RAID striped is for performance and you would notice apps loading faster .. I also feel it's more trouble than it's worth in a desktop setup .. for a server it can useful

You don't really need to have both disks the same size but it is highly, highly recommended that you do have two *identical* drives .. as in the same make/model/size .. also your motherboard must have a RAID controller or you're going to have to buy a PCI RAID controller card

 

If you're concerned about your hard drive performance I would suggest buying diskeeper pro or O & O Defragmenter .. as they will be cheaper and a lot easier to use and even if you set up a RAID striped volume, it's not going to use it's full potential if you are relying on the built-in windows defragmenter

 

I personally wouldn't ever consider raid 1 in a server. Raid 5 would be my choice in a server situation.

Just my two cents.

Also, Raid 0 (Stripe) does have "some" benefits. Video editing. Audio encoding. That is about it.

Raid 1 (mirror) is about the best choice for a backup. If one drive fails, you still have the other. Break array, replace drive, recreate array, bosses happy.