RAID, or Redundant Array of Independent Disks, is a technology of keeping data on multiple hard disks which operate together as one single logical unit. The drives could be physical or logical i.e. in the aforementioned case one single drive is split into independent ones through virtualization software. In any case, the very same information is kept on all drives and the basic advantage of employing this type of a setup is that in case a drive breaks down, the data will remain available on the other ones. Using a RAID also boosts the overall performance as the input and output operations will be spread among a couple of drives. There are several kinds of RAID based on how many hard drives are used, whether writing is performed on all of the drives in real time or just on one, and how the data is synced between the drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. These factors mean that the error tolerance as well as the performance between the various RAID types could differ.
RAID in Web Hosting
The state-of-the-art cloud hosting platform where all web hosting accounts are made employs super fast SSD drives as an alternative to the traditional HDDs, and they function in RAID-Z. With this setup, numerous hard disk drives operate together and at least one of them is a dedicated parity disk. In simple terms, when data is written on the remaining drives, it's duplicated on the parity one adding an extra bit. This is done for redundancy as even if some drive fails or falls out of the RAID for some reason, the data can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, therefore practically nothing will be lost and there will be no service disturbances. This is another level of protection for your info along with the revolutionary ZFS file system that uses checksums to make sure that all data on our servers is intact and is not silently corrupted.