RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to take advantage of a number of hard drives as a single logical unit. To put it differently, all drives are used as one and the info on all of them is identical. This kind of a setup has two key advantages over using just a single drive to keep data - the first one is redundancy, so if one drive breaks down, the data will be accessed through the remaining ones, and the second is improved performance because the input/output, or reading/writing operations will be distributed among a number of drives. There're different RAID types depending on how many drives are used, if reading and writing are both performed 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, etc. Based on the exact setup, the fault tolerance and the performance could differ.
RAID in Shared Hosting
The hard drives that we employ for storage with our outstanding cloud Internet hosting platform are not the standard 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. Any content that you upload to your shared hosting
account will be held on multiple hard drives and at least one of them will be employed as a parity disk. This is a specific drive where an additional bit is added to any content copied on it. In case a disk in the RAID stops functioning, it will be replaced without any service disturbances and the info will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the remaining disks. This is done in order to ensure the integrity of the data and along with the real-time checksum validation which the ZFS file system executes on all drives, you will never have to worry about the loss of any info no matter what.
RAID in Semi-dedicated Servers
The SSD drives which are used for saving any site content uploaded to the semi-dedicated server
accounts that we offer work in RAID-Z. This is a special setup where one or more drives are used for parity i.e. the system will include an additional bit to any data cloned on this type of a disk drive. In case that a disk fails and is replaced with a new one, what information will be cloned on the latter will be a combination calculated between the data on the other drives and that on the parity one. This is done to guarantee that the information on the new drive shall be accurate. Throughout the process, the RAID will continue operating adequately and the faulty drive will not affect the adequate operation of your websites in any way. Working with SSDs in RAID-Z is an excellent addition to the ZFS file system that runs on our revolutionary cloud platform with regards to preserving the integrity of your files as ZFS uses special digital identifiers called checksums in order to avoid silent data corruption.