RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that allows a system to use a number of hard drives as one single logical unit. In other words, all the drives are used as one and the info on all of them is the same. This type of a configuration has 2 key advantages over using just a single drive to store data - the first one is redundancy, so in the event that one drive fails, the info will be accessible from the remaining ones, and the second one is improved performance since the input/output, or reading/writing operations will be spread among several drives. You can find different RAID types based on the number of drives are employed, if reading and writing are both performed from all the drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etc. According to the particular setup, the error tolerance and the performance may differ.
RAID in Shared Hosting
The state-of-the-art cloud web hosting platform where all shared hosting accounts are generated employs quick SSD drives as an alternative to the standard HDDs, and they work in RAID-Z. With this configuration, 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 rest of the drives, it's copied on the parity one adding an extra bit. This is carried out for redundancy as even in case a drive fails or falls out of the RAID for some reason, the information can be rebuilt and verified thanks to the parity disk and the data recorded on the other ones, therefore nothing will be lost and there won't be any service disorders. This is an additional level of protection for your data together with the revolutionary ZFS file system which uses checksums to make sure that all of the data on our servers is undamaged and is not silently corrupted.
RAID in Semi-dedicated Hosting
The RAID type which we employ for the cloud Internet hosting platform where your semi-dedicated hosting account shall be created is named RAID-Z. What is different about it is that at least 1 of the disks is used as a parity drive. In simple terms, whenever any data is cloned on this specific disk drive, one more bit is included to it and in the event that a defective disk is replaced, the info that will be duplicated on it is a mix of the data on the remaining drives in the RAID and that on the parity one. We do this to ensure that the data is intact. During this process, your Internet sites will be functioning normally since RAID-Z makes it possible for an entire drive to fail without service disturbances and it simply uses one of the remaining ones as the main production drive. Using RAID-Z together with the ZFS file system which uses checksums to warrant that no data shall get silently corrupted on our servers, you will never need to worry about the integrity of your files.