Redundant Array of Independent Disks, or RAID, is a method of saving content on a number of hard drives concurrently. A RAID can be software or hardware depending on the hard drives which are used - physical or logical ones, yet what is common between them is the fact that they all operate as a single unit where information is kept. The top advantage of employing a RAID is redundancy as the information on all of the drives shall be exactly the same all the time, so even if a drive fails for whatever reason, the information will still be available on the remaining drives. The overall performance is enhanced as well because the reading and writing processes could be split between different drives, so a single one will never be overloaded. There are different kinds of RAIDs where the efficiency and fault tolerance may differ based on the specific setup - whether information is written on all drives real-time or it's written on a single drive and afterwards mirrored on another, what amount of drives are used for the RAID, and so on.
RAID in Website Hosting
The hard drives which we employ for storage with our revolutionary cloud hosting platform are not the standard HDDs, but high-speed solid-state drives (SSD). They function in RAID-Z - a special setup developed for the ZFS file system which we use. All of the content that you upload to the website hosting account will be kept on multiple disk drives and at least 1 shall be employed as a parity disk. This is a special drive where an extra bit is included to any content copied on it. In case a disk in the RAID stops working, it'll be replaced without any service disturbances and the information will be recovered on the new drive by recalculating its bits using the data on the parity disk along with that on the other disks. This is done in order to guarantee the integrity of the info and together with the real-time checksum validation that the ZFS file system performs on all drives, you will never need to concern yourself with losing any info no matter what.