RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to take advantage of many hard drives as a single logical unit. In other words, all drives are used as one and the info on all of them is identical. This type of a setup has 2 major advantages over using a single drive to store data - the first is redundancy, so in the event that one drive breaks down, the data will be accessible through the others, and the second one is improved performance since the input/output, or reading/writing operations will be spread among several drives. There're different RAID types based on the number of drives are used, whether reading and writing are both performed from all drives at the same time, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and many others. Based on the particular setup, the error tolerance and the performance may differ.
RAID in Hosting
The state-of-the-art cloud hosting platform where all hosting accounts are generated employs super fast SSD drives as an alternative to the standard HDDs, and they operate in RAID-Z. With this configuration, a number of hard disk drives function together and at least one of them is a dedicated parity disk. In simple terms, when data is written on the other drives, it is cloned on the parity one adding an extra bit. This is performed for redundancy as even if a drive fails or falls out of the RAID for some reason, the information can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, which means that practically nothing will be lost and there won't be any service interruptions. This is another level of security for your info together with the revolutionary ZFS file system which uses checksums to ensure that all of the data on our servers is intact and is not silently corrupted.