RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that allows a system to use many hard drives as one single logical unit. Put simply, all the drives are used as one and the data on all of them is the same. This type of a configuration has two key advantages over using a single drive to store data - the first one is redundancy, so in case one drive breaks down, the info will be accessible through the remaining ones, and the second one is improved performance because the input/output, or reading/writing operations will be distributed among different drives. There're different RAID types based on the number of drives are employed, whether reading and writing are both handled from all of the drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Depending on the particular setup, the fault tolerance and the performance vary.
RAID in Web Hosting
Our cutting-edge cloud Internet hosting platform where all web hosting accounts are made uses super fast SSD drives rather than the classic HDDs, and they operate in RAID-Z. With this configuration, a number of hard disks function together and at least one is a dedicated parity disk. In simple terms, when data is written on the rest of the drives, it is copied on the parity one adding an extra bit. This is carried out for redundancy as even if a drive fails or falls out of the RAID for some reason, the data can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, thus not a single thing will be lost and there will be no service disorders. This is an additional level of protection for your data in addition to the top-notch ZFS file system that uses checksums to guarantee that all the data on our servers is intact and is not silently corrupted.