RAID, or Redundant Array of Independent Disks, is a technology of storing data on multiple hard disks that function together as a single logical unit. The drives could be physical or logical i.e. in the aforementioned case a single drive is split into independent ones through virtualization software. Either way, exactly the same information is saved on all drives and the basic benefit of employing such a setup is that if a drive stops working, the data will still be available on the remaining ones. Using a RAID also improves the overall performance as the input and output operations will be spread among a couple of drives. There are several types of RAID dependant upon how many hard drives are used, whether writing is performed on all drives in real time or just on one, and how the info is synced between the drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. These factors imply that the error tolerance as well as the performance between the various RAID types may differ.
RAID in Hosting
The SSD drives which our cutting-edge cloud Internet hosting platform uses for storage work in RAID-Z. This kind of RAID is designed to work with the ZFS file system which runs on the platform and it works by using the so-called parity disk - a special drive where data kept on the other drives is cloned with an additional bit added to it. If one of the disks stops functioning, your Internet sites shall continue working from the other ones and once we replace the problematic one, the info which will be duplicated on it will be recovered from what is stored on the other drives together with the info from the parity disk. This is performed in order to be able to recalculate the elements of every file adequately and to validate the integrity of the information copied on the new drive. This is an additional level of security for the info you upload to your hosting account together with the ZFS file system that analyzes a special digital fingerprint for each and every file on all the disk drives in real time.