RAID, or Redundant Array of Independent Disks, is a technology for storing data on multiple hard drives that work together as one logical unit. The drives could be physical or logical i.e. in the second case one single drive is split into independent ones using virtualization software. In any case, the same info is kept on all of the drives and the basic advantage of using this type of a setup is that in the event that a drive fails, the data shall still be available on the remaining ones. Having a RAID also boosts the overall performance because the input and output operations will be spread among a few drives. There are several types of RAID depending on how many hard disks are used, whether writing is carried out on all drives in real time or just on one, and how the data is synced between the drives - whether it's recorded in blocks on one drive after another or it is mirrored from one on the others. All these factors indicate that the fault tolerance as well as the performance between the different RAID types can vary.
RAID in Cloud Hosting
The SSD drives which our cutting-edge cloud web hosting platform uses for storage function in RAID-Z. This sort of RAID is intended to work with the ZFS file system which runs on the platform and it uses the so-called parity disk - a special drive where info stored on the other drives is duplicated with an extra bit added to it. If one of the disks fails, your websites shall continue working from the other ones and after we replace the faulty one, the data that will be cloned on it will be rebuilt from what is stored on the other drives as well as the info from the parity disk. This is done so as to be able to recalculate the elements of every single file adequately and to verify the integrity of the information copied on the new drive. This is another level of security for the info you upload to your cloud hosting account in addition to the ZFS file system that analyzes a special digital fingerprint for each and every file on all the hard drives in real time.