If your Hard Drive fails and you have no backups then you will lose all your files. One solution to this is to have a RAID (Redundant Array of Independent Disks) system, especially if your motherboard supports it.
RAID uses two or more Hard Drives to protect your data and/or speed up disk access depending on the level of RAID that is used. The most common levels of RAID are RAID 0, RAID 1, and RAID 5.
RAID 0 uses 'striping' which combines two or more disks and improves disk access speed by breaking data up into equal sized chunks which are written alternately across all the disks. Although this improves performance and gives you additional storage if one Hard Drive fails then you cannot recover this data.
RAID 1 uses 'mirroring' by duplicating your data to two Hard Disks so if one Hard Drive fails then you still have your data safe on the other.
RAID 5 uses 'striping' but also distributes 'parity' along with the data so that if one Hard Drive fails then the data can still be recovered by calculating the distributed parity. This gives you the advantage of striping but with the ability to recover data if one Hard Drive fails but a minimum of three Hard Drives are required.
Can i add a RAID system to my computer?
More recent mid-range or high-end motherboards usually include a RAID controller. You will need to consult your motherboard manual to see if it includes RAID and which levels it supports.
If your motherboard does not support RAID, then you can buy a PCI or PCIe RAID expansion card.
Lastly, most operating systems provide a software solution for setting up a RAID array so that you do not need any hardware. The performance benefit of a software RAID is dependant on the overall speed of the computer.
Do i need a RAID system?
A RAID system can increase the performance of reading and writing data to your Hard Drive but today's drives are already quite fast or installing a Solid State Drive (SSD) will considerable increase disk access speed.
RAID can protect data in the case of a Hard Drive failure but if you routinely back-up your important files then you may not need a RAID system. Using RAID (mirroring) is not a substitute for backing up your files because, for example, if you accidentally deleted an important file then it will be removed from both mirrored copies. Also if a file is corrupted by a virus then it will be copied to both disks.
Setting up a RAID system.
Before setting up a RAID system it is extremely important to back up all your important files and keep them somewhere safe.
It is a good idea to use identical Hard Drives in your RAID system which are the same make, model, and have the same capacity. Mixing Hard Drives used to cause problems, and although it is not so much of a problem today, it is still recommended that you use identical Drives.
Follow anti-static procedures and install your new identical Hard Drives into your computer and connect the power and data cables. If you have a RAID expansion card then install it according to the manufacturer's directions.
Boot your computer and enter the CMOS setup screen and make sure the BIOS can see your new Hard Drives. If your motherboard supports RAID then you will find a RAID page on the CMOS setup screen where you can configure it properly. See motherboard manual.
If you have installed a RAID expansion card then it will most likely have its own BIOS which will load a RAID configuration page on startup. Refer to the manufacturer's instructions.
When installing the operating system then you will be asked to press F6 (Windows XP only) where you can install the RAID drivers. Windows Vista and Windows 7 will display a screen asking where to install the operating system which will also include a button called 'load Driver' where you can install the RAID drivers. Follow the on-screen instructions and complete the operating system installation.