RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that allows a system to use many hard drives as one single logical unit. Put simply, all drives are used as one and the data on all of them is the same. Such a setup has two huge advantages over using a single drive to store data - the first one is redundancy, so in the event that one drive stops working, 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 a number of drives. There are different RAID types in accordance with what amount of drives are employed, if reading and writing are both handled from all the drives simultaneously, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and many others. Determined by the particular setup, the fault tolerance and the performance may differ.
RAID in Shared Hosting
The NVMe drives that our cutting-edge cloud hosting platform uses for storage function in RAID-Z. This sort of RAID is created to work with the ZFS file system that runs on the platform and it employs the so-called parity disk - a special drive where data located on the other drives is duplicated with an additional bit added to it. In case one of the disks stops functioning, your sites will continue working from the other ones and after we replace the malfunctioning one, the data that will be copied on it will be recovered from what is stored on the other drives along with the information from the parity disk. This is performed so as to be able to recalculate the elements of every single file properly and to validate the integrity of the info duplicated on the new drive. This is an additional level of security for the information that you upload to your shared hosting account in addition to the ZFS file system that compares a special digital fingerprint for each file on all drives in real time.
RAID in Semi-dedicated Servers
The RAID type that we use for the cloud web hosting platform where your semi-dedicated server account shall be created is named RAID-Z. What's different about it is that at least 1 of the disks is employed as a parity drive. Put simply, whenever any kind of data is cloned on this specific disk drive, one more bit is added to it and in case a faulty disk is changed, the data which will be copied on it is a mix of the data on the remaining hard disks in the RAID and that on the parity one. We do this to ensure that the info is intact. During this process, your sites will be up and running normally since RAID-Z allows for a whole drive to fail without service disruptions and it simply works by using one of the remaining ones as the main production drive. Employing RAID-Z together with the ZFS file system that uses checksums to ensure that no data will get silently corrupted on our servers, you will not need to worry about the integrity of your files.