RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to use a number of hard drives as one single logical unit. To put it differently, all of the drives are used as one and the information on all of them is the same. This type of a configuration has 2 huge advantages over using just a single drive to keep data - the first one is redundancy, so in the event that one drive fails, the data will be accessed through the remaining ones, and the second one is better performance because the input/output, or reading/writing operations will be distributed among several drives. There're different RAID types depending on what amount of drives are used, whether reading and writing are both done from all of 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, and many others. Based on the particular setup, the error tolerance and the performance could differ.
RAID in Website Hosting
All content which you upload to your new website hosting account will be held on quick SSD drives which operate in RAID-Z. This setup is built to use the ZFS file system that runs on our cloud web hosting platform and it adds one more level of security for your site content in addition to the real-time checksum validation that ZFS uses to guarantee the integrity of the data. With RAID-Z, the info is saved on a couple of disks and at least 1 is a parity disk - whenever info is written on it, an extra bit is added, so in the event that any drive stops working for some reason, the integrity of the data can be verified by recalculating its bits in accordance with what is stored on the production hard disks and on the parity one. With RAID-Z, the operation of our system won't be interrupted and it'll continue working efficiently until the faulty drive is changed and the information is synced on it.