RAID, or Redundant Array of Independent Disks, is a technology for storing data on a number hard drives that work together as one single logical unit. The drives can be physical or logical i.e. in the second case one drive is split into individual ones through virtualization software. Either way, the very same info is stored on all drives and the key benefit of employing this type of a setup is that in case a drive stops working, the data will still be available on the other ones. Using a RAID also improves the performance as the input and output operations will be spread among a number of drives. There are several types of RAID depending on how many hard disks are used, whether writing is done on all of the drives in real time or just on one, and how the data is synchronized between the 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 show that the fault tolerance and the performance between the various RAID types can vary.
RAID in Website Hosting
The hard drives that we employ for storage with our state-of-the-art cloud Internet hosting platform are not the standard HDDs, but high-speed solid-state drives (SSD). They work in RAID-Z - a special setup created for the ZFS file system that we employ. All of the content that you upload to your website hosting
account will be stored on multiple disk drives and at least 1 will be employed as a parity disk. This is a special drive where a further bit is included to any content copied on it. In the event that a disk in the RAID fails, it'll be replaced with no service interruptions and the info will be recovered on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the other disks. This is done to guarantee the integrity of the info and along with the real-time checksum authentication that the ZFS file system performs on all drives, you won't ever need to be concerned about losing any information no matter what.
RAID in Semi-dedicated Servers
The SSD drives which are used for holding any content uploaded to the semi-dedicated server
accounts that we offer function in RAID-Z. This is a specific configuration where one or more hard drives are used for parity i.e. the system will add an extra bit to any data copied on such a drive. If a disk fails and is replaced with a new one, what info will be duplicated on the latter will be a combination calculated between the data on the remaining hard disks and that on the parity one. This is done to guarantee that the information on the new drive will be correct. Throughout the procedure, the RAID will continue operating normally and the faulty drive will not have an effect on the normal operation of your sites in any way. Working with SSDs in RAID-Z is a fantastic addition to the ZFS file system which runs on our advanced cloud platform with regards to preserving the integrity of your files as ZFS uses special digital identifiers called checksums so as to prevent silent data corruption.