RAID, or Redundant Array of Independent Disks, is a technology for saving data on a number hard drives which operate together as one single logical unit. The drives can be physical or logical i.e. in the latter case a single drive is split into different ones via virtualization software. In either case, the very same info is saved on all the drives and the key advantage of using this kind of a setup is that if a drive breaks down, the data will remain available on the remaining ones. Having a RAID also boosts the performance since the input and output operations will be spread among a couple of drives. There are several types of RAID based on how many hard drives are used, whether writing is done on all drives in real time or just on a single one, and how the information is synced between the drives - whether it's written in blocks on one drive after another or it is mirrored from one on the others. All these factors show that the error tolerance and the performance between the various RAID types may differ.
RAID in Website Hosting
The hard disks which we use for storage with our outstanding cloud Internet hosting platform are not the classic HDDs, but high-speed solid-state drives (SSD). They work in RAID-Z - a special setup developed for the ZFS file system that we employ. Any content that you upload to your website hosting account will be stored on multiple drives and at least one shall be used as a parity disk. This is a special drive where an additional bit is included to any content copied on it. In case a disk in the RAID stops working, it will be changed without service disruptions and the info will be rebuilt on the new drive by recalculating its bits using the data on the parity disk along with that on the other disks. This is done in order to ensure the integrity of the info and along with the real-time checksum verification that the ZFS file system executes on all drives, you'll never have to be concerned about losing any info no matter what.