RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to use multiple hard drives as a single logical unit. In other words, all the drives are used as one and the data on all of them is the same. This kind of a configuration has two key advantages over using a single drive to save data - the first is redundancy, so in the event that one drive fails, the info will be accessible from the others, and the second is improved performance as the input/output, or reading/writing operations will be spread among several drives. You can find different RAID types depending on what amount of drives are employed, whether reading and writing are both executed from all the drives at the same time, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. According to the particular setup, the fault tolerance and the performance may vary.
RAID in Web Hosting
The disk drives which we employ for storage with our state-of-the-art cloud hosting platform are not the traditional HDDs, but super fast solid-state drives (SSD). They function in RAID-Z - a special setup intended for the ZFS file system that we work with. All of the content that you upload to the web hosting account will be kept on multiple hard drives and at least 1 shall be used as a parity disk. This is a specific drive where a further bit is included to any content copied on it. If a disk in the RAID stops working, it'll be replaced without service interruptions and the info will be rebuilt on the new drive by recalculating its bits using the data on the parity disk plus that on the remaining disks. This is done so as to ensure the integrity of the data and along with the real-time checksum validation which the ZFS file system performs on all drives, you'll never need to worry about the loss of any data no matter what.
RAID in Semi-dedicated Hosting
The SSD drives which are used for storing any content uploaded to the semi-dedicated hosting accounts that we provide operate in RAID-Z. This is a special setup where one or more hard drives are employed for parity i.e. the system will include an extra bit to any data cloned on this type of a hard drive. In the event that a disk fails and is replaced with another one, what info will be duplicated on the latter shall be a mix calculated between the data on the remaining drives and that on the parity one. This is done to make sure that the information on the new drive will be correct. Throughout the process, the RAID will continue working adequately and the problematic drive won't impact the normal operation of your sites by any means. Using SSDs in RAID-Z is an impressive addition to the ZFS file system which runs on our cutting-edge cloud platform with respect to preserving the integrity of your files as ZFS uses specific digital identifiers known as checksums so as to prevent silent data corruption.
RAID in VPS Web Hosting
The SSD drives that we use on the machines where we generate virtual private servers work in RAID to make sure that any content you upload will be available and intact all the time. At least a single drive is used for parity - one bit of data is added to any data cloned on it. In case a main drive fails, it is replaced and the data which will be copied on it is calculated between the other drives and the parity one. It's done this way to ensure that the needed information is copied and that no file is corrupted because the new drive will be included in the RAID afterwards. We also use hard disk drives working in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you will use an even more reliable Internet hosting service because your content will be available on multiple drives irrespective of any type of unexpected hardware failure.