RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to use several hard drives as one single logical unit. Simply put, all of the drives are used as one and the data on all of them is the same. Such a setup has 2 major advantages over using a single drive to store data - the first one is redundancy, so in case one drive doesn't work, the information will be accessible from the others, and the second is better performance as the input/output, or reading/writing operations will be spread among different drives. There are different RAID types in accordance with the number of drives are used, whether reading and writing are both handled from all drives at the same time, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and so on. Depending on the particular setup, the fault tolerance and the performance may differ.
RAID in Web Hosting
The hard drives that we use for storage with our top-notch cloud web hosting platform are not the classic HDDs, but high-speed solid-state drives (SSD). They function in RAID-Z - a special setup developed for the ZFS file system that we work with. All of the content that you add to your web hosting account will be held on multiple hard drives and at least one of them shall be employed as a parity disk. This is a specific drive where an extra bit is included to any content copied on it. In the event that a disk in the RAID fails, it will be replaced without service interruptions and the info will be recovered on the new drive by recalculating its bits using the data on the parity disk plus that on the remaining disks. This is done in order to ensure the integrity of the info and together with the real-time checksum validation that the ZFS file system performs on all drives, you'll never have to concern yourself with losing any info no matter what.
RAID in Semi-dedicated Hosting
The information uploaded to any semi-dedicated hosting account is stored on SSD drives which function in RAID-Z. One of the drives in this kind of a setup is used for parity - whenever data is cloned on it, an additional bit is added. In case a disk turns out to be defective, it will be removed from the RAID without disturbing the operation of the Internet sites as the data will load from the remaining drives, and when a brand new drive is included, the data that will be copied on it will be a blend between the data on the parity disk and data stored on the other drives in the RAID. That is done in order to guarantee that the data that is being cloned is accurate, so once the new drive is rebuilt, it could be included in the RAID as a production one. This is an extra warranty for the integrity of your info since the ZFS file system that runs on our cloud web hosting platform analyzes a special checksum of all the copies of your files on the separate drives to be able to avoid any possibility of silent data corruption.
RAID in VPS Hosting
The SSD drives that we use on the physical machines where we create virtual private servers function in RAID to ensure that any content which you upload will be available and intact at all times. At least a single drive is employed for parity - one bit of information is added to any data cloned on it. In case a main drive fails, it is replaced and the data that will be cloned on it is calculated between the rest of the drives and the parity one. That’s done to ensure that the right data is copied and that no file is corrupted since the new drive will be used in the RAID afterwards. In addition, we use hard disks operating in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you shall use an even more reliable web hosting service because your content will be available on multiple drives irrespective of any sort of unforeseen hardware malfunction.