RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which allows a system to use several 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. Such a configuration has two major advantages over using a single drive to store data - the first one is redundancy, so in case one drive stops working, the data will be accessible from the others, and the second one is improved performance because the input/output, or reading/writing operations will be spread among several drives. There are different RAID types based on what amount of drives are employed, if reading and writing are both done 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, and so on. Determined by the exact setup, the error tolerance and the performance may differ.
RAID in Shared Hosting
Any content that you upload to your new shared hosting account will be placed on fast SSD drives that function in RAID-Z. This configuration is built to work with the ZFS file system that runs on our cloud Internet hosting platform and it adds one more level of protection for your website content on top of the real-time checksum validation that ZFS uses to ensure the integrity of the data. With RAID-Z, the data is saved on a number of disks and at least one of them is a parity disk - whenever info is recorded on it, an additional bit is added, so if any drive stops working for whatever reason, the integrity of the data can be verified by recalculating its bits based on what is saved on the production drives and on the parity one. With RAID-Z, the operation of our system will not be interrupted and it will continue functioning smoothly until the problematic drive is changed and the information is synchronized on it.