RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to employ many hard drives as one single logical unit. Put simply, all the drives are used as one and the info on all of them is identical. This kind of a setup has two huge advantages over using a single drive to save data - the first is redundancy, so if one drive doesn't work, the info will be accessed from the remaining ones, and the second is improved performance since the input/output, or reading/writing operations will be spread among several drives. There're different RAID types based on how many drives are used, if reading and writing are both handled from all drives at the same time, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Determined by the particular setup, the fault tolerance and the performance may differ.
RAID in Shared Web Hosting
Our cutting-edge cloud web hosting platform where all shared web hosting accounts are created uses quick SSD drives instead of the traditional HDDs, and they operate in RAID-Z. With this setup, a number of hard disk drives work together and at least 1 is a dedicated parity disk. Basically, when data is written on the remaining drives, it is cloned on the parity one adding an extra bit. This is performed for redundancy as even in case 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 recorded on the other ones, therefore absolutely nothing will be lost and there won't be any service disturbances. This is one more level of protection for your data along with the state-of-the-art ZFS file system that uses checksums to make sure that all of the data on our servers is undamaged and is not silently corrupted.