RAID, or Redundant Array of Independent Disks, is a technology of keeping data on a number hard disks that operate together as one logical unit. The drives could be physical or logical i.e. in the aforementioned case one drive is divided into individual ones using virtualization software. Either way, the very same information is stored on all of the drives and the main benefit of employing this kind of a setup is that if a drive stops working, the data will remain available on the other ones. Using a RAID also enhances the overall performance as the input and output operations will be spread among a few drives. There are several kinds of RAID depending on how many hard disks are used, whether writing is performed on all the drives in real time or just on a single one, and how the info is synchronized between the hard drives - whether it is written in blocks on one drive after another or it is mirrored from one on the others. All these factors mean that the fault tolerance and the performance between the different RAID types may differ.
RAID in Cloud Web Hosting
The disk drives which we employ for storage with our innovative cloud hosting platform are not the traditional HDDs, but extremely fast solid-state drives (SSD). They operate in RAID-Z - a special setup developed for the ZFS file system which we use. All the content that you upload to your cloud web hosting account will be held on multiple disk drives and at least one of them shall be used 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 stops functioning, it'll be changed with no service disruptions and the data 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 so as to guarantee the integrity of the info and together with the real-time checksum validation that the ZFS file system runs on all drives, you'll never have to concern yourself with losing any data no matter what.