Redundant Array of Independent Disks, or RAID, is a way of keeping content on multiple hard disks concurrently. A RAID can be software or hardware based on the drives which are used - physical or logical ones, yet what’s common between them is that they all function as just one single unit where data is kept. The key advantage of using a RAID is redundancy as the info on all the drives is exactly the same all the time, so even if a drive fails for whatever reason, the data will still be available on the rest of the drives. The overall performance is also enhanced because the reading and writing processes could be split between multiple drives, so a single one won't be overloaded. There're different sorts of RAIDs where the performance and fault tolerance may vary depending on the exact setup - whether info is written on all drives real-time or it is written on a single drive and then mirrored on another, the number of drives are used for the RAID, etc.
RAID in Cloud Hosting
The advanced cloud web hosting platform where all cloud hosting accounts are created employs fast SSD drives rather than the traditional HDDs, and they operate in RAID-Z. With this setup, a number of hard drives operate together and at least 1 is a dedicated parity disk. Simply put, when data is written on the rest of the drives, it's copied on the parity one adding an extra bit. This is done for redundancy as even if some drive fails or falls out of the RAID for whatever reason, the data can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, which means that absolutely nothing will be lost and there will be no service disorders. This is another level of security for your info in addition to the revolutionary ZFS file system that uses checksums to guarantee that all of the data on our servers is undamaged and is not silently corrupted.