RAID, or Redundant Array of Independent Disks, is a technology for keeping data on several hard disks that work together as a single logical unit. The drives could be physical or logical i.e. in the latter case one single drive is divided into independent ones using virtualization software. Either way, identical data is stored on all of the drives and the main benefit of using such a setup is that in case a drive breaks down, the data will remain available on the remaining ones. Employing a RAID also improves the overall performance as the input and output operations will be spread among a couple of drives. There are several kinds of RAID dependant upon how many hard drives are used, whether writing is performed on all of 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 it is mirrored from one on the others. All of these factors show that the fault tolerance and the performance between the various RAID types may differ.
RAID in Cloud Hosting
The SSD drives that 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 employs the so-called parity disk - a special drive where information saved on the other drives is cloned with an additional bit added to it. In the event that one of the disks stops functioning, your Internet sites will continue working from the other ones and as soon as we replace the bad one, the information which will be cloned on it will be rebuilt from what is stored on the remaining drives along with the info from the parity disk. This is done so as to be able to recalculate the elements of each file correctly and to confirm the integrity of the info duplicated on the new drive. This is another level of security for the info you upload to your cloud hosting account along with the ZFS file system which compares a special digital fingerprint for each file on all of the disk drives in real time.