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 several hard drives as one single logical unit. Simply put, all drives are used as one and the information on all of them is identical. Such a setup has 2 huge advantages over using a single drive to keep data - the first one is redundancy, so in case one drive fails, the data will be accessed through the others, and the second is better performance as the input/output, or reading/writing operations will be spread among a number of drives. You can find different RAID types depending on what amount of drives are employed, whether reading and writing are both done from all drives simultaneously, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, and many others. Based on the particular setup, the error tolerance and the performance may vary.
RAID in Shared Web Hosting
The SSD drives that our cutting-edge cloud hosting platform uses for storage operate in RAID-Z. This kind of RAID is intended to work with the ZFS file system which runs on the platform and it takes advantage of the so-called parity disk - a specific drive where info kept on the other drives is duplicated with an additional bit added to it. In the event that one of the disks stops working, your Internet sites will continue working from the other ones and after we replace the malfunctioning one, the data which will be duplicated on it will be rebuilt from what is stored on the rest of the drives along with the info from the parity disk. This is done in order to be able to recalculate the bits of every single file properly and to validate the integrity of the data copied on the new drive. This is another level of security for the information you upload to your shared web hosting account together with the ZFS file system that compares a unique digital fingerprint for each and every file on all disk drives in real time.