RAID, or Redundant Array of Independent Disks, is a technology for saving data on a number hard disks which work together as a single logical unit. The drives can be physical or logical i.e. in the aforementioned case a single drive is divided into different ones using virtualization software. In any case, the very same data is saved on all drives and the main benefit of employing this type of a setup is that if a drive stops working, the data will remain available on the other ones. Employing a RAID also enhances the overall performance as the input and output operations will be spread among several drives. There are several types of RAID depending on how many hard disks are used, whether writing is performed on all the drives in real time or just on one, and how the info is synchronized between the hard drives - whether it's written in blocks on one drive after another or it is mirrored from one on the others. All of these factors show that the error tolerance and the performance between the various RAID types could differ.
RAID in Hosting
The hard disks which we employ for storage with our outstanding cloud web hosting platform are not the classic HDDs, but quick solid-state drives (SSD). They operate in RAID-Z - a special setup developed for the ZFS file system that we employ. All of the content that you upload to your hosting
account will be stored on multiple hard drives and at least one of them shall be employed 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 functioning, it'll be changed without any service interruptions and the information will be recovered on the new drive by recalculating its bits using the data on the parity disk plus that on the remaining disks. This is done so as to ensure the integrity of the data and together with the real-time checksum validation which the ZFS file system performs on all drives, you'll never need to worry about the loss of any information no matter what.
RAID in Semi-dedicated Hosting
The RAID type which we employ for the cloud web hosting platform where your semi-dedicated hosting
account shall be created is known as RAID-Z. What's different about it is that at least one of the disks is used as a parity drive. Put simply, whenever any data is cloned on this special drive, one more bit is added to it and in the event that a malfunctioning disk is replaced, the data which will be cloned on it is a mix of the data on the remaining drives in the RAID and that on the parity one. We do this to ensure that the info is intact. During this process, your Internet sites will be functioning normally since RAID-Z allows for a whole drive to fail without causing any service disturbances and it simply uses one of the other ones as the main production drive. Using RAID-Z together with the ZFS file system which uses checksums to ensure that no data can get silently corrupted on our servers, you will not need to worry about the integrity of your files.
RAID in VPS Hosting
The SSD drives which we use on the machines where we create virtual private servers
function in RAID to ensure that any content you upload will be available and intact at all times. At least one drive is used for parity - one bit of data is added to any data cloned on it. In the event that a main drive breaks down, it is changed and the info that will be cloned on it is calculated between the other drives and the parity one. It's done this way to make sure that the right info is copied and that not a single file is corrupted since the new drive will be included in 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 shall use an even more reliable Internet hosting service as your content will be available on multiple drives regardless of any kind of unforeseen hardware failure.