RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which makes it possible for a system to employ many hard drives as a single logical unit. To put it differently, all drives are used as one and the information on all of them is the same. Such a setup has 2 key advantages over using a single drive to store data - the first one is redundancy, so if one drive doesn't work, the information will be accessed from the remaining ones, and the second is better performance since the input/output, or reading/writing operations will be spread among several drives. You can find different RAID types depending on the number of drives are used, whether reading and writing are both handled from all the drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, and so on. According to the particular setup, the fault tolerance and the performance may differ.
RAID in Hosting
Our revolutionary cloud web hosting platform where all hosting accounts are made uses fast SSD drives as opposed to the standard HDDs, and they function in RAID-Z. With this configuration, a number of hard disk drives operate together and at least 1 is a dedicated parity disk. Simply put, when data is written on the other drives, it's cloned on the parity one adding an extra bit. This is done for redundancy as even in case a drive fails or falls out of the RAID for whatever reason, the data can be rebuilt and verified using the parity disk and the data recorded on the other ones, which means that practically nothing will be lost and there will not be any service disturbances. This is another level of security for your information in addition to the state-of-the-art ZFS file system which uses checksums to ensure that all the data on our servers is intact and is not silently corrupted.