RAID, or Redundant Array of Independent Disks, is a technology for saving data on several hard drives which work together as one single logical unit. The drives could be physical or logical i.e. in the second case a single drive is split into separate ones via virtualization software. In either case, the same data is stored on all of the drives and the basic benefit of using such a setup is that in case a drive fails, the data will remain available on the remaining ones. Having a RAID also improves the performance since the input and output operations will be spread among a couple of drives. There are several kinds of RAID based on how many drives are used, whether writing is performed on all the drives in real time or just on one, and how the info is synced between the drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors show that the fault tolerance as well as the performance between the different RAID types may vary.
RAID in Shared Web Hosting
The NVMe drives that our cutting-edge cloud hosting platform uses for storage work in RAID-Z. This type of RAID is created to work with the ZFS file system which runs on the platform and it uses 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 case one of the disks stops working, your websites shall continue working from the other ones and as soon as we replace the problematic one, the info which will be copied on it will be rebuilt from what is stored on the other drives together with the information from the parity disk. This is performed so as to be able to recalculate the bits of every single file properly and to authenticate the integrity of the information cloned on the new drive. This is another level of security for the content which you upload to your shared web hosting account along with the ZFS file system which analyzes a unique digital fingerprint for every single file on all the disk drives in real time.