RAID, or Redundant Array of Independent Disks, is a technology for keeping data on a number hard drives that operate together as one single logical unit. The drives could be physical or logical i.e. in the second case one single drive is split into independent ones via virtualization software. Either way, exactly the same data is stored on all drives and the key benefit of employing such a setup is that if a drive stops working, the data will still be available on the remaining ones. Using a RAID also boosts the overall performance because the input and output operations will be spread among a few drives. There are several types of RAID based on how many hard disks are used, whether writing is carried out on all drives in real time or just on a single one, and how the info is synced between the drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. These factors show that the fault tolerance and the performance between the different RAID types can differ.
RAID in Cloud Web Hosting
The hard disks that we employ for storage with our revolutionary cloud Internet hosting platform are not the classic HDDs, but quick solid-state drives (SSD). They function in RAID-Z - a special setup designed for the ZFS file system which we work with. All of the content that you add to your cloud web hosting account will be held on multiple hard drives and at least one shall be employed as a parity disk. This is a special drive where a further bit is included to any content copied on it. If a disk in the RAID stops functioning, it will be replaced without any service interruptions and the information will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the other disks. This is done in order to guarantee the integrity of the information and together with the real-time checksum validation which the ZFS file system performs on all drives, you will never need to concern yourself with the loss of any information no matter what.