RAID, or Redundant Array of Independent Disks, is a technology for saving data on several hard disks which operate together as one single logical unit. The drives can be physical or logical i.e. in the aforementioned case a single drive is divided into separate ones through virtualization software. In either case, the very same info is stored on all the drives and the key advantage of using such a setup is that in case a drive breaks down, the data shall still be available on the other ones. Using a RAID also enhances the overall performance because the input and output operations will be spread among several drives. There are several kinds of RAID based on how many hard drives are used, whether writing is performed on all the drives in real time or just on a single one, and how the data is synchronized between the hard drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors mean that the fault tolerance as well as the performance between the various RAID types could differ.
RAID in Cloud Hosting
The SSD drives which our cutting-edge cloud web hosting platform uses for storage operate in RAID-Z. This type of RAID is designed to work with the ZFS file system that runs on the platform and it uses the so-called parity disk - a special drive where information saved on the other drives is duplicated with an extra bit added to it. In case one of the disks stops working, your sites shall continue working from the other ones and as soon as we replace the problematic one, the information that will be cloned on it will be recovered from what is stored on the other drives together with the information from the parity disk. This is done so as to be able to recalculate the bits of each file adequately and to authenticate the integrity of the information copied on the new drive. This is one more level of security for the content that you upload to your cloud hosting account together with the ZFS file system which analyzes a unique digital fingerprint for each and every file on all drives in real time.