RAID, or Redundant Array of Independent Disks, is a technology for keeping data on multiple hard disk drives which function together as one logical unit. The drives can be physical or logical i.e. in the second case a single drive is split into separate ones via virtualization software. Either way, the same data is stored on all drives and the main advantage of using this type of a setup is that in case a drive breaks down, the data will remain available on the remaining ones. Having a RAID also improves the overall performance since the input and output operations will be spread among a number of drives. There are several types of RAID based on how many hard disks are used, whether writing is done on all drives in real time or just on a single one, and how the data is synced between the drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. These factors imply that the error tolerance and the performance between the different RAID types can differ.
RAID in Cloud Web Hosting
The advanced cloud web hosting platform where all cloud web hosting accounts are created uses super fast SSD drives instead of the traditional HDDs, and they function in RAID-Z. With this configuration, multiple hard drives operate together and at least a single one is a dedicated parity disk. Basically, when data is written on the rest of the drives, it is duplicated on the parity one adding an extra bit. This is done for redundancy as even if some drive fails or falls out of the RAID for some reason, the data can be rebuilt and verified thanks to the parity disk and the data recorded on the other ones, which means that not a thing will be lost and there will not be any service interruptions. This is one more level of security for your data in addition to the advanced ZFS file system which uses checksums to make sure that all the data on our servers is intact and is not silently corrupted.