RAID, or Redundant Array of Independent Disks, is a technology for keeping data on multiple hard disks that operate together as a single logical unit. The drives can be physical or logical i.e. in the latter case one drive is divided into different ones via virtualization software. Either way, the very same data is kept on all the drives and the key advantage of using this kind of a setup is that in the event that a drive fails, the data will still be available on the other ones. Using a RAID also improves the performance because the input and output operations will be spread among a few drives. There are several kinds of RAID dependant upon how many hard drives are used, whether writing is carried out on all drives in real time or just on a single one, and how the data is synced between the drives - whether it is written in blocks on one drive after another or it is mirrored from one on the others. All of these factors show that the fault tolerance as well as the performance between the different RAID types can differ.

RAID in Web Hosting

The SSD drives that our cutting-edge cloud Internet hosting platform uses for storage work in RAID-Z. This type of RAID is created to work with the ZFS file system which runs on the platform and it employs the so-called parity disk - a specific drive where information saved on the other drives is cloned with an additional bit added to it. In the event that one of the disks stops working, your sites shall continue working from the other ones and after we replace the bad one, the data that will be copied on it will be recovered from what is stored on the remaining drives as well as the info from the parity disk. This is done in order to be able to recalculate the bits of every file properly and to confirm the integrity of the information copied on the new drive. This is an additional level of security for the content which you upload to your web hosting account in addition to the ZFS file system which analyzes a unique digital fingerprint for every single file on all of the hard drives in real time.

RAID in Semi-dedicated Servers

The RAID type which we use for the cloud web hosting platform where your semi-dedicated server 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 kind of data is duplicated on this specific drive, one more bit is included to it and in the event that a malfunctioning disk is changed, the information which will be copied on it is a mix of the data on the other disk drives in the RAID and that on the parity one. This is done to guarantee that your data is intact. During this process, your Internet sites will be functioning normally as RAID-Z enables a whole drive to fail without any service interruptions 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 guarantee that no data can get silently corrupted on our servers, you will never need to worry about the integrity of your files.