RAID
What is RAID? What are the benefits of a RAID-equipped server?
Redundant Array of Independent Disks, or RAID, is a way of saving content on several hard disks at the same time. A RAID can be software or hardware depending on the drives which are used - physical or logical ones, however what’s common between them is the fact that they all operate as just a single unit where information is saved. The top advantage of employing a RAID is redundancy as the data on all of the drives will be identical all of the time, so even in the event that some drive fails for some reason, the information will still be available on the other drives. The general performance is also better as the reading and writing processes can be split between different drives, so a single one won't be overloaded. There're different sorts of RAIDs where the capabilities and fault tolerance may differ depending on the exact setup - whether info is written on all drives in real time or it is written on one drive and after that mirrored on another, what amount of drives are used for the RAID, etcetera.