RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that allows a system to employ a number of hard drives as one single logical unit. Simply put, all drives are used as one and the data on all of them is the same. This kind of a setup has 2 key advantages over using a single drive to store data - the first is redundancy, so in case one drive fails, the information will be accessed through the remaining ones, and the second one is improved performance because the input/output, or reading/writing operations will be distributed among multiple drives. There're different RAID types in accordance with what number of drives are used, if reading and writing are both performed from all drives simultaneously, whether 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 fault tolerance and the performance may differ.
RAID in Cloud Hosting
Any content which you upload to your new cloud hosting account will be saved on quick SSD drives that operate in RAID-Z. This setup is built to work with the ZFS file system which runs on our cloud hosting platform and it adds one more level of protection for your website content in addition to the real-time checksum authentication which ZFS uses to guarantee the integrity of the data. With RAID-Z, the information is stored on a couple of disks and at least one is a parity disk - whenever data is written on it, an extra bit is added, so in case any drive stops working for whatever reason, the stability of the data can be verified by recalculating its bits based on what is stored on the production hard disks and on the parity one. With RAID-Z, the operation of our system will never be interrupted and it will continue functioning efficiently until the faulty drive is replaced and the data is synchronized on it.