RAID, or Redundant Array of Independent Disks, is a technology for keeping data on a number hard disk drives that operate together as one logical unit. The drives can be physical or logical i.e. in the latter case a single drive is split into individual ones via virtualization software. In either case, identical info is kept on all of the drives and the main advantage of employing this type of a setup is that in the event that a drive stops working, the data will still be available on the remaining ones. Using a RAID also improves the overall performance because the input and output operations will be spread among a few drives. There are several types of RAID based on 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 recorded in blocks on one drive after another or all of it is mirrored from one on the others. All these factors imply that the error tolerance and the performance between the various RAID types can differ.
RAID in Shared Hosting
The NVMe drives which our cutting-edge cloud Internet hosting platform employs for storage work in RAID-Z. This type of RAID is designed 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 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 websites will continue working from the other ones and once we replace the malfunctioning one, the data that will be copied on it will be recovered from what is stored on the rest of the drives together with the data from the parity disk. This is done so as to be able to recalculate the elements of every single file properly and to verify the integrity of the data cloned on the new drive. This is an additional level of security for the information that you upload to your shared hosting account together with the ZFS file system that analyzes a special digital fingerprint for each file on all of the hard drives in real time.