RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which enables a system to take advantage of multiple hard drives as a single logical unit. In other words, all of the drives are used as one and the information on all of them is the same. This type of a configuration has two major advantages over using just a single drive to store data - the first one is redundancy, so in the event that one drive breaks down, the information will be accessible from the remaining ones, and the second is better performance since the input/output, or reading/writing operations will be distributed among multiple drives. You can find different RAID types depending on what number of drives are employed, whether reading and writing are both handled 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. Based on the particular setup, the fault tolerance and the performance vary.
RAID in Web Hosting
All of the content that you upload to your new web hosting account will be held on fast SSD drives which work 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 authentication which ZFS uses to guarantee the integrity of the data. With RAID-Z, the information is saved on a number of disks and at least one is a parity disk - whenever data is written on it, an additional bit is added, so if any drive fails for whatever reason, the stability of the info can be verified by recalculating its bits based on what is kept on the production hard disks and on the parity one. With RAID-Z, the operation of our system will never be interrupted and it'll continue operating smoothly until the malfunctioning drive is changed and the information is synced on it.