RAID, or Redundant Array of Independent Disks, is a technology for keeping data on multiple hard drives which function together as a single logical unit. The drives can be physical or logical i.e. in the second case one drive is divided into different ones via virtualization software. In either case, the same info is kept on all the drives and the key advantage of using this kind of a setup is that if a drive fails, the data will remain available on the other ones. Employing a RAID also improves the performance since the input and output operations will be spread among several drives. There are several kinds of RAID dependant upon how many hard disks are used, whether writing is done on all drives in real time or just on a single one, and how the data is synced between the hard drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors show that the error tolerance as well as the performance between the different RAID types could differ.
RAID in Website Hosting
The disk drives which we use for storage with our ground-breaking cloud hosting platform are not the traditional HDDs, but high-speed solid-state drives (SSD). They operate in RAID-Z - a special setup intended for the ZFS file system which we work with. Any content that you upload to the website hosting account will be kept on multiple drives and at least one of them will be used as a parity disk. This is a special drive where an additional 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 interruptions 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 data and together with the real-time checksum authentication which the ZFS file system performs on all drives, you'll never need to be concerned about losing any info no matter what.