RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to use several hard drives as a single logical unit. To put it differently, all drives are used as one and the info on all of them is identical. Such a setup has 2 huge advantages over using a single drive to store data - the first one is redundancy, so in case one drive doesn't work, the data 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 multiple drives. You can find different RAID types in accordance with how many 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 so on. Depending on the particular setup, the error tolerance and the performance could differ.
RAID in Shared Hosting
The cutting-edge cloud hosting platform where all shared hosting accounts are created employs super fast SSD drives as opposed to the traditional HDDs, and they work in RAID-Z. With this setup, a number of hard disks work together and at least one of them is a dedicated parity disk. Put simply, when data is written on the remaining drives, it is cloned on the parity one adding an extra bit. This is carried out for redundancy as even if some drive fails or falls out of the RAID for some reason, the info can be rebuilt and verified thanks to the parity disk and the data recorded on the other ones, which means that not a thing will be lost and there will not be any service disturbances. This is one more level of security for your information in addition to the state-of-the-art ZFS file system which uses checksums to make sure that all the data on our servers is undamaged and is not silently corrupted.