RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that permits a system to employ a number of hard drives as one single logical unit. Put simply, all of the drives are used as one and the info on all of them is identical. This type of a setup has two key advantages over using a single drive to save data - the first is redundancy, so in the event that one drive doesn't work, the data will be accessed through the remaining ones, and the second is better performance since the input/output, or reading/writing operations will be spread among a number of drives. There're different RAID types in accordance with what amount of drives are used, whether reading and writing are both handled from all drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etc. According to the exact setup, the error tolerance and the performance may vary.
RAID in Shared Hosting
The revolutionary cloud Internet hosting platform where all shared hosting accounts are made employs super fast NVMe drives rather than the standard HDDs, and they work in RAID-Z. With this configuration, numerous hard disk drives function together and at least 1 is a dedicated parity disk. Simply put, when data is written on the remaining drives, it's cloned on the parity one adding an extra bit. This is performed for redundancy as even if some drive fails or falls out of the RAID for whatever reason, the info can be rebuilt and verified thanks to the parity disk and the data recorded on the other ones, thus not a single thing will be lost and there won't be any service disturbances. This is one more level of protection for your information along with the top-notch ZFS file system which uses checksums to make sure that all of the data on our servers is intact and is not silently corrupted.