RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which allows a system to take advantage of multiple hard drives as one single logical unit. Simply put, all of the drives are used as one and the info on all of them is identical. This type of a configuration has two key advantages over using just a single drive to save data - the first one is redundancy, so in the event that one drive doesn't work, the information will be accessible from the remaining ones, and the second one is improved performance because the input/output, or reading/writing operations will be distributed among different drives. There're different RAID types based on what amount of drives are employed, whether reading and writing are both performed from all of the drives concurrently, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and many others. Depending on the exact setup, the fault tolerance and the performance may vary.
RAID in Hosting
Any content that you upload to your new hosting account will be held on quick SSD drives that work in RAID-Z. This configuration is built to work with the ZFS file system which runs on our cloud hosting platform and it adds an additional level of security for your content on top of the real-time checksum authentication which ZFS uses to ensure the integrity of the data. With RAID-Z, the info is stored on a number of disks and at least 1 is a parity disk - whenever data is recorded on it, an extra bit is added, so if any drive fails for some reason, the stability of the information can be verified by recalculating its bits in accordance with what is saved on the production hard drives and on the parity one. With RAID-Z, the functioning of our system will never be interrupted and it will continue functioning flawlessly until the problematic drive is changed and the information is synchronized on it.