RAID, or Redundant Array of Independent Disks, is a technology of storing data on a number hard disk drives which operate together as one single logical unit. The drives can be physical or logical i.e. in the latter case one drive is divided into independent ones using virtualization software. Either way, the same data is saved on all the drives and the key advantage of employing such a setup is that in case a drive fails, the data will remain available on the remaining ones. Having a RAID also enhances the performance since the input and output operations will be spread among a few drives. There are several types of RAID dependant upon how many hard disks are used, whether writing is performed on all of the drives in real time or just on one, and how the information is synchronized between the hard drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors imply that the error tolerance and the performance between the different RAID types may differ.
RAID in Cloud Hosting
The SSD drives which our cutting-edge cloud Internet hosting platform employs for storage operate in RAID-Z. This sort of RAID is created to work with the ZFS file system which runs on the platform and it works by using the so-called parity disk - a special drive where data stored on the other drives is duplicated with an additional bit added to it. In case one of the disks stops working, your sites will continue working from the other ones and once we replace the faulty one, the info which will be duplicated on it will be recovered from what is stored on the other drives together with the data from the parity disk. This is done in order to be able to recalculate the bits of each file adequately and to verify the integrity of the info copied on the new drive. This is one more level of security for the info you upload to your cloud hosting account together with the ZFS file system which analyzes a unique digital fingerprint for each file on all the drives in real time.