Harddisk-RAID
There are six different levels of RAID:
1.) RAID 0 - This level requires a minimum of two disks. It does provide improved performance, but it doesn't account for data repetition or failures. With this level, data striping is used so that the data is all split up onto the two disks. So, yes, this method does work at a very high level of performance, but if either of the drives fail, all of that data will be lost for good. I guess there's always a price to pay.
2.) RAID 1 - This level is a mirrored set of two disks in which the data is replicated to separate hard disks in real time. It's done that way to ensure continuous availability, currency and accuracy. This level does provide fault tolerance in case any disk errors or failures occur.
3.) RAID 3 and 4 - These two levels are combined together in a set of three or more disks. One of those disks is mainly used for error checking, so if that particular one fails, the other two will be able to continue working without the error checking function. On the other hand, if one of the data drives itself fails, all of the RAID data will be lost.
4.) RAID 5 - This level is also a set of three or more disks, but for this method, the error checking disk is split up between all three drives. In that case, one single drive failure can be handled, but if more than one drive fails, all of the RAID data will be lost.
5.) RAID 6 - This last level is a set of four disks (minimum) and two of them are used for error checking only. With that being multiplied, the RAID system can still operate if two of the other drives fail. Once one of the drives is replaced, the data can still be saved and it is then split up between all of the RAID drives.
Now, the level of RAID you should use depends on what you do with your computer. For example, if you do a lot of video processing or gaming, you're going to want a more reliable RAID system, such as level 5 or 6. If you do a lot of banking and online shopping with your computer, you will want a safer RAID system, so the mirrored option of level 1 may be your best bet. It all depends on your computing activities.
RAID systems are available for Windows, Mac OS X and Linux operating systems. Now, if you're interested in getting one for your computer, I would definitely suggest looking into it a little more. You can certainly use this tip as a reference, but you'll want to do some of your own researching as well. RAID is an inexpensive way to go, but you have to make sure it's going to work well enough for you and your computer. I must admit though, it's a very interesting concept and if any of you use RAID or plan to in the near future, I'd love to hear about it!