RAID, or Redundant Array of Independent Disks, is a technology for keeping data on several hard disks which operate together as one logical unit. The drives can be physical or logical i.e. in the latter case one drive is split into different ones via virtualization software. In either case, the very same information is kept on all of the drives and the basic advantage of using this kind of a setup is that in case a drive breaks down, the data shall still be available on the remaining ones. Having a RAID also boosts the performance as the input and output operations will be spread among a number of drives. There are several kinds of RAID based on 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 information is synchronized between the hard drives - whether it is recorded in blocks on one drive after another or it is mirrored from one on the others. These factors mean that the fault tolerance and the performance between the various RAID types may differ.
RAID in Shared Website Hosting
The NVMe drives that our cutting-edge cloud Internet hosting platform uses for storage operate in RAID-Z. This sort of RAID is intended to work with the ZFS file system that runs on the platform and it employs the so-called parity disk - a specific drive where information stored on the other drives is duplicated with an additional bit added to it. In case one of the disks stops functioning, your sites shall continue working from the other ones and once we replace the faulty one, the information which will be cloned on it will be recovered from what is stored on the rest of the drives as well as the information from the parity disk. This is performed so as to be able to recalculate the elements of every single file properly and to validate the integrity of the info cloned on the new drive. This is an additional level of security for the info you upload to your shared website hosting account together with the ZFS file system that compares a unique digital fingerprint for each file on all of the drives in real time.