Redundant Array of Independent Disks, or RAID, is a way of keeping content on a number of hard disks simultaneously. A RAID can be software or hardware depending on the HDDs that are used - physical or logical ones, yet what’s common between them is that they all function as just one single unit where data is saved. The top advantage of using a RAID is redundancy since the information on all of the drives is the same all the time, so even if one of the drives fails for whatever reason, the info will still be available on the rest of the drives. The overall performance is enhanced as well since the reading and writing processes will be split between different drives, so a single one won't be overloaded. There're different sorts of RAIDs where the efficiency and fault tolerance can vary based on the specific setup - whether information is written on all drives 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.
RAID in Web Hosting
The hard disks which we employ for storage with our innovative cloud Internet hosting platform are not the classic HDDs, but high-speed solid-state drives (SSD). They operate in RAID-Z - a special setup developed for the ZFS file system that we employ. All of the content that you add to the web hosting account will be held on multiple hard disks and at least one of them shall be employed as a parity disk. This is a specific drive where an extra bit is included to any content copied on it. In the event that a disk in the RAID fails, it will be replaced without any service disruptions and the info will be rebuilt on the new drive by recalculating its bits using the data on the parity disk plus that on the remaining disks. This is done in order to ensure the integrity of the data and together with the real-time checksum validation which the ZFS file system performs on all drives, you won't ever need to worry about the loss of any info no matter what.