RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that permits a system to use several hard drives as one single logical unit. In other words, all the drives are used as one and the information on all of them is the same. Such a setup has two major advantages over using just a single drive to store data - the first is redundancy, so in the event that one drive fails, the data will be accessible through the remaining ones, and the second one is better performance since the input/output, or reading/writing operations will be spread among different drives. There're different RAID types depending on how many drives are employed, if reading and writing are both executed from all the drives simultaneously, 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 fault tolerance and the performance vary.
RAID in Shared Website Hosting
The cutting-edge cloud hosting platform where all shared website hosting accounts are generated employs quick SSD drives as an alternative to the traditional HDDs, and they work in RAID-Z. With this setup, multiple hard disks operate together and at least a single one is a dedicated parity disk. Put simply, when data is written on the rest of the drives, it's 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 whatever reason, the information can be rebuilt and verified using the parity disk and the data saved on the other ones, which means that not a thing will be lost and there will not be any service interruptions. This is another level of protection for your info together with the revolutionary ZFS file system that uses checksums to guarantee that all data on our servers is intact and is not silently corrupted.