RAID, or Redundant Array of Independent Disks, is a technology for keeping data on multiple hard disk drives which operate together as a single logical unit. The drives can be physical or logical i.e. in the latter case one single drive is divided into individual ones through virtualization software. In either case, exactly the same info is stored on all of the drives and the key advantage of employing this type of a setup is that in the event that a drive breaks down, the data will remain available on the remaining ones. Using a RAID also improves the performance as the input and output operations will be spread among a couple of drives. There are several kinds of RAID depending on how many hard drives are used, whether writing is carried out on all the drives in real time or just on one, and how the data is synchronized 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. All of these factors imply that the error tolerance and the performance between the different RAID types can vary.
RAID in Shared Website Hosting
The cutting-edge cloud web hosting platform where all shared website hosting accounts are made employs quick SSD drives as an alternative to the classic HDDs, and they function in RAID-Z. With this setup, multiple hard disk drives work together and at least one is a dedicated parity disk. In simple terms, when data is written on the other 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 whatever reason, the info can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, so nothing will be lost and there will not be any service interruptions. This is an additional level of protection for your info in addition to the cutting-edge ZFS file system that uses checksums to guarantee that all the data on our servers is intact and is not silently corrupted.