RAID, or Redundant Array of Independent Disks, is a technology of keeping data on a number hard disks that function together as one single logical unit. The drives can be physical or logical i.e. in the aforementioned case a single drive is divided into individual ones via virtualization software. Either way, the same data is kept on all drives and the key advantage of employing this type of a setup is that if a drive breaks down, the data will remain available on the remaining ones. Using a RAID also improves the performance since the input and output operations will be spread among a number of drives. There are several kinds of RAID depending on how many hard drives are used, whether writing is performed on all of the drives in real time or just on a single one, and how the data is synced 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 suggest that the error tolerance as well as the performance between the various RAID types can vary.
RAID in Shared Web Hosting
The NVMe drives that our cutting-edge cloud Internet hosting platform employs for storage operate in RAID-Z. This kind of RAID is designed to work with the ZFS file system which runs on the platform and it takes advantage of the so-called parity disk - a special drive where information located on the other drives is copied with an additional bit added to it. If one of the disks stops working, your sites shall continue working from the other ones and as soon as we replace the problematic one, the information that 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 done so as to be able to recalculate the elements of every single file correctly and to authenticate the integrity of the info cloned on the new drive. This is one more level of security for the content that you upload to your shared web hosting account along with the ZFS file system that compares a special digital fingerprint for every single file on all the disk drives in real time.