Redundant Array of Independent Disks, or RAID, is a way of storing content on a number of hard drives concurrently. A RAID could be software or hardware based on the hard drives which are used - physical or logical ones, still what is common between them is that they all function as just one single unit where your information is saved. The biggest advantage of employing a RAID is redundancy since the data on all of the drives shall be exactly the same all of the time, so even in the event that some drive fails for some reason, the data will still be available on the rest of the drives. The overall performance is also enhanced because the reading and writing processes will be split between different drives, so a single one won't be overloaded. There're different types of RAIDs where the effectiveness and fault tolerance may differ according to the exact setup - whether information is written on all of the 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 many others.
RAID in Web Hosting
The drives which we employ for storage with our ground-breaking cloud web hosting platform are not the standard HDDs, but high-speed solid-state drives (SSD). They function in RAID-Z - a special setup intended for the ZFS file system that we work with. All the content that you upload to your web hosting account will be saved on multiple hard disks and at least one will be employed as a parity disk. This is a special drive where an additional bit is added to any content copied on it. In case a disk in the RAID fails, it will be replaced with no service disturbances and the data will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk along with that on the remaining disks. This is done to ensure the integrity of the info and along with the real-time checksum validation which the ZFS file system executes on all drives, you'll never need to be concerned about the loss of any info no matter what.