RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to use many hard drives as a single logical unit. To put it differently, all the drives are used as one and the info on all of them is identical. This type of a configuration has two major advantages over using a single drive to keep data - the first is redundancy, so in case one drive breaks down, the info will be accessed from the remaining ones, and the second one is improved performance as the input/output, or reading/writing operations will be spread among different drives. You can find different RAID types depending on how many drives are used, if reading and writing are both handled from all the 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, etc. According to the particular setup, the error tolerance and the performance may differ.
RAID in Hosting
Our revolutionary cloud web hosting platform where all hosting accounts are created uses fast SSD drives instead of the traditional HDDs, and they function in RAID-Z. With this configuration, multiple hard drives operate together and at least one of them is a dedicated parity disk. Simply put, when data is written on the rest of the drives, it is 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 some reason, the data can be rebuilt and verified thanks to the parity disk and the data saved on the other ones, so practically nothing will be lost and there will not be any service interruptions. This is one more level of protection for your info together with the state-of-the-art ZFS file system that uses checksums to ensure that all of the data on our servers is undamaged and is not silently corrupted.