RAID, or Redundant Array of Independent Disks, is a technology of keeping data on multiple hard disk drives that work together as one single logical unit. The drives could be physical or logical i.e. in the latter case a single drive is divided into independent ones via virtualization software. In either case, the same information is stored on all drives and the main benefit of employing this kind of a setup is that in case a drive stops working, the data shall still be available on the other ones. Employing a RAID also boosts the overall performance as the input and output operations will be spread among several drives. There are several kinds of RAID dependant upon how many hard disks are used, whether writing is carried out on all drives in real time or just on one, and how the information is synced 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 these factors mean that the fault tolerance and the performance between the various RAID types may vary.
RAID in Cloud Website Hosting
The cutting-edge cloud hosting platform where all cloud website hosting accounts are created employs super fast SSD drives instead of the classic HDDs, and they operate in RAID-Z. With this setup, a number of hard disk drives operate together and at least a single one is a dedicated parity disk. Simply put, when data is written on the remaining drives, it is cloned on the parity one adding an extra bit. This is performed for redundancy as even in case a drive fails or falls out of the RAID for some reason, the info can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, thus not a thing will be lost and there won't be any service interruptions. This is an additional level of protection for your info in addition to the advanced ZFS file system that uses checksums to make sure that all of the data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Servers
The SSD drives which are used for saving any website content uploaded to the semi-dedicated server accounts which we provide function in RAID-Z. This is a specific setup where one or more disk drives are employed for parity i.e. the system will add an additional bit to any data copied on this kind of a drive. In case that a disk fails and is substituted with a new one, what info will be duplicated on the latter shall be a mix calculated between the data on the remaining hard disks and that on the parity one. This is done to guarantee that the data on the new drive shall be correct. During the procedure, the RAID will continue working normally and the faulty drive will not have an effect on the proper operation of your Internet sites in any way. Using SSDs in RAID-Z is a great addition to the ZFS file system which runs on our advanced cloud platform with regards to preserving the integrity of your files because ZFS uses specific digital identifiers called checksums so as to prevent silent data corruption.