Redundant Array of Independent Disks, or RAID, is a method of saving content on multiple hard disks concurrently. A RAID might be software or hardware depending on the HDDs that are used - physical or logical ones, yet what is common between them is that they all perform as just a single unit where info is kept. The key advantage of using a RAID is redundancy because the info on all of the drives will be identical at all times, so even in case a drive fails for some reason, the info will still be present on the other drives. The overall performance will also improve as the reading and writing processes will be split between various drives, so a single one will never be overloaded. There are different sorts of RAIDs where the effectiveness and fault tolerance may differ depending on the exact setup - whether information is written on all of the drives in real time or it is written on a single drive and after that mirrored on another, what number of drives are used for the RAID, and so on.
RAID in Web Hosting
The revolutionary cloud hosting platform where all web hosting accounts are made uses quick SSD drives as an alternative to the traditional HDDs, and they work in RAID-Z. With this setup, multiple hard disks operate together and at least 1 is a dedicated parity disk. In simple terms, when data is written on the remaining drives, it's duplicated 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 information 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 disturbances. This is another level of protection for your information along with the top-notch ZFS file system that uses checksums to ensure that all data on our servers is intact and is not silently corrupted.