RAID, or Redundant Array of Independent Disks, is a technology of keeping data on a number hard disk drives which work together as a single logical unit. The drives can be physical or logical i.e. in the latter case one drive is divided into different ones via virtualization software. In any case, the same info is saved on all the drives and the key advantage of employing this kind of a setup is that in case a drive fails, the data shall still be available on the other ones. Using a RAID also enhances the overall performance as the input and output operations will be spread among a couple of drives. There are several kinds of RAID dependant upon how many hard drives are used, whether writing is carried out on all of the drives in real time or just on a single one, and how the info is synchronized between the drives - whether it is written in blocks on one drive after another or it is mirrored from one on the others. These factors show that the error tolerance as well as the performance between the various RAID types could differ.
RAID in Web Hosting
The disk drives that we employ for storage with our ground-breaking cloud hosting platform are not the standard HDDs, but extremely fast NVMes. They work in RAID-Z - a special setup created for the ZFS file system which we work with. All 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 used as a parity disk. This is a special drive where a further bit is included to any content copied on it. In the event that a disk in the RAID stops functioning, it will be changed without service disruptions and the data will be recovered on the new drive by recalculating its bits using the data on the parity disk plus that on the other disks. This is done to guarantee the integrity of the information and together with the real-time checksum verification that the ZFS file system performs on all drives, you will never have to worry about the loss of any information no matter what.