RAID, or Redundant Array of Independent Disks, is a technology for saving data on a number hard disks which work together as a single logical unit. The drives could be physical or logical i.e. in the aforementioned case one single drive is divided into different ones through virtualization software. In either case, exactly the same data is stored on all the drives and the main advantage of using this type of a setup is that if a drive fails, the data will remain available on the other ones. Having a RAID also enhances the performance because the input and output operations will be spread among a couple of drives. There are several types of RAID based on how many hard drives are used, whether writing is carried out on all the drives in real time or just on a single one, and how the data is synced between the drives - whether it is recorded in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors indicate that the fault tolerance and the performance between the different RAID types could differ.
RAID in Shared Web Hosting
The SSD drives that our cutting-edge cloud web hosting platform employs for storage work in RAID-Z. This sort of RAID is intended 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 info located on the other drives is copied with an additional bit added to it. In the event that one of the disks stops functioning, your Internet sites shall continue working from the other ones and after we replace the faulty one, the data which will be copied on it will be recovered from what is stored on the other drives together with the data from the parity disk. This is performed so as to be able to recalculate the elements of each file properly and to verify the integrity of the data copied on the new drive. This is one more level of security for the information which you upload to your shared web hosting account in addition to the ZFS file system that compares a special digital fingerprint for each and every file on all drives in real time.