RAID, or Redundant Array of Independent Disks, is a technology for saving data on a number hard drives that work together as a single logical unit. The drives could be physical or logical i.e. in the aforementioned case a single drive is divided into individual ones using virtualization software. Either way, exactly the same info is kept on all drives and the basic benefit of employing such a setup is that in case a drive stops working, the data will remain available on the remaining ones. Using a RAID also boosts the performance as the input and output operations will be spread among a number of drives. There are several kinds of RAID depending on how many drives are used, whether writing is done on all the drives in real time or just on a single one, and how the data is synced between the drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. These factors mean that the fault tolerance as well as the performance between the various RAID types could differ.
RAID in Website Hosting
The cutting-edge cloud hosting platform where all website hosting accounts are made uses fast SSD drives as opposed to the standard HDDs, and they operate in RAID-Z. With this setup, a number of hard drives operate together and at least one is a dedicated parity disk. Put simply, when data is written on the rest of the drives, it's copied on the parity one adding an extra bit. This is carried out for redundancy as even if a drive fails or falls out of the RAID for some reason, the info can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, thus not a single thing will be lost and there won't be any service interruptions. This is one more level of security for your information in addition to the advanced ZFS file system that uses checksums to guarantee that all data on our servers is undamaged and is not silently corrupted.