RAID, or Redundant Array of Independent Disks, is a technology of saving data on a number hard disks that function together as one single logical unit. The drives could be physical or logical i.e. in the second case one single drive is divided into different ones using virtualization software. Either way, the same data is saved on all drives and the main benefit of employing this kind of a setup is that in case a drive fails, the data will remain available on the remaining ones. Having a RAID also enhances the performance as the input and output operations will be spread among a couple of drives. There are several kinds of RAID based on how many drives are used, whether writing is carried out on all the drives in real time or just on a single one, and how the info is synchronized between the hard drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors indicate that the fault tolerance and the performance between the different RAID types may vary.
RAID in Website Hosting
The drives which we employ for storage with our outstanding cloud Internet hosting platform are not the classic HDDs, but extremely fast solid-state drives (SSD). They work in RAID-Z - a special setup created for the ZFS file system that we employ. All the content that you upload to your website hosting account will be stored on multiple hard drives and at least one shall be employed as a parity disk. This is a specific drive where an additional bit is included to any content copied on it. In case a disk in the RAID stops functioning, it'll be replaced without any service interruptions and the data will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the remaining disks. This is done so as to ensure the integrity of the info and along with the real-time checksum verification that the ZFS file system runs on all drives, you'll never have to be concerned about losing any info no matter what.