RAID, or Redundant Array of Independent Disks, is a technology of keeping data on several hard disk drives that operate together as one logical unit. The drives could be physical or logical i.e. in the aforementioned case one single drive is divided into individual ones through virtualization software. In either case, the same info is kept on all of the drives and the main advantage of using such a setup is that if a drive stops working, the data will remain available on the remaining ones. Employing a RAID also enhances the performance because the input and output operations will be spread among several drives. There are several kinds of RAID dependant upon how many hard drives are used, whether writing is done on all the drives in real time or just on one, and how the info is synced between the drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors show that the error tolerance and the performance between the different RAID types can differ.
RAID in Web Hosting
Any content that you upload to your new web hosting account will be held on quick SSD drives that operate in RAID-Z. This setup is built to employ the ZFS file system that runs on our cloud web hosting platform and it adds an additional level of security for your site content on top of the real-time checksum verification which ZFS uses to ensure the integrity of the data. With RAID-Z, the data is saved on several disks and at least one is a parity disk - whenever information is written on it, an additional bit is added, so in case any drive stops functioning for whatever reason, the stability of the data can be verified by recalculating its bits based on what is saved on the production hard disks 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 faulty drive is changed and the information is synchronized on it.