RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that makes it possible for a system to employ several hard drives as one single logical unit. To put it differently, all drives are used as one and the data on all of them is the same. This kind of a setup has 2 major advantages over using a single drive to store data - the first is redundancy, so in case one drive stops working, the information will be accessible through the remaining ones, and the second is improved performance since the input/output, or reading/writing operations will be spread among different drives. There're different RAID types based on what number of drives are employed, whether reading and writing are both done from all the drives simultaneously, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Determined by the exact setup, the error tolerance and the performance may differ.
RAID in Shared Hosting
The NVMe drives which our cutting-edge cloud hosting platform uses for storage operate in RAID-Z. This kind of RAID is developed to work with the ZFS file system which runs on the platform and it uses the so-called parity disk - a special drive where data kept on the other drives is duplicated with an additional bit added to it. If one of the disks stops functioning, your websites shall continue working from the other ones and after we replace the malfunctioning one, the info which will be copied on it will be recovered from what is stored on the remaining drives as well as the data from the parity disk. This is performed so as to be able to recalculate the elements of every file adequately and to validate the integrity of the info copied on the new drive. This is another level of security for the info which you upload to your shared hosting account together with the ZFS file system that analyzes a special digital fingerprint for every single file on all of the drives in real time.