RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to use multiple hard drives as a single logical unit. To put it differently, all of the drives are used as one and the information on all of them is identical. Such a configuration has 2 major advantages over using just a single drive to keep data - the first one is redundancy, so in case one drive doesn't work, the information will be accessed from the others, and the second is improved performance because the input/output, or reading/writing operations will be distributed among several drives. There are different RAID types in accordance with how many drives are employed, whether reading and writing are both done from all drives simultaneously, if data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. According to the particular setup, the fault tolerance and the performance may differ.
RAID in Shared Website Hosting
Our state-of-the-art cloud hosting platform where all shared website hosting accounts are generated employs fast SSD drives instead of the traditional HDDs, and they work in RAID-Z. With this configuration, a number of hard disk drives work together and at least a single one is a dedicated parity disk. Put simply, when data is written on the remaining drives, it's duplicated 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 thanks to the parity disk and the data saved on the other ones, which means that absolutely nothing will be lost and there won't be any service disturbances. This is another level of protection for your data in addition to the advanced ZFS file system which uses checksums to make sure that all data on our servers is undamaged and is not silently corrupted.