RAID, or Redundant Array of Independent Disks, is a technology of storing data on multiple hard disk drives which operate together as a single logical unit. The drives could be physical or logical i.e. in the second case one single drive is split into separate ones via virtualization software. In any case, exactly the same information is saved on all of the drives and the main advantage of employing such a setup is that if a drive stops working, the data will remain available on the remaining ones. Having a RAID also boosts the overall performance as the input and output operations will be spread among a number of drives. There are several kinds of RAID based on how many hard disks are used, whether writing is performed on all drives in real time or just on one, and how the information is synced between the hard drives - whether it's recorded in blocks on one drive after another or it is mirrored from one on the others. These factors imply that the error tolerance and the performance between the various RAID types may differ.
RAID in Shared Web Hosting
The NVMe drives which our cutting-edge cloud Internet hosting platform employs for storage operate in RAID-Z. This type of RAID is intended to work with the ZFS file system that runs on the platform and it employs the so-called parity disk - a special drive where info saved on the other drives is copied with an extra bit added to it. In the event that one of the disks fails, your Internet sites shall continue working from the other ones and once we replace the faulty one, the data that will be copied on it will be recovered from what is stored on the remaining drives together with the information from the parity disk. This is done so as to be able to recalculate the bits of every file properly and to validate the integrity of the information cloned on the new drive. This is another level of security for the content that you upload to your shared web hosting account along with the ZFS file system that compares a unique digital fingerprint for each and every file on all the disk drives in real time.
RAID in VPS Web Hosting
The NVMe drives that we use on the machines where we generate virtual private servers operate in RAID to ensure that any content which you upload will be available and intact all of the time. At least a single drive is used for parity - one bit of data is added to any data cloned on it. In case a main drive stops working, it is changed and the data which will be cloned on it is calculated between the other drives and the parity one. This is done to ensure that the right info is copied and that not a single file is corrupted because the new drive will be a part of the RAID afterwards. We also use hard disks operating in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you'll use an even more reliable Internet hosting service since your content will be available on multiple drives regardless of any sort of unforeseen hardware failure.