RAID, or Redundant Array of Independent Disks, is a technology for storing data on a number hard disks which function together as a single logical unit. The drives can be physical or logical i.e. in the latter case a single drive is divided into individual ones using virtualization software. Either way, the same data is stored on all drives and the key advantage of employing this kind of a setup is that if a drive fails, the data shall still be available on the other ones. Employing a RAID also enhances the performance since the input and output operations will be spread among a number of drives. There are several kinds of RAID based on how many hard drives are used, whether writing is carried out on all the drives in real time or just on one, and how the info is synchronized between the drives - whether it is recorded in blocks on one drive after another or all of it is mirrored from one on the others. All these factors mean that the error tolerance and 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 operate in RAID-Z. This kind of RAID is designed to work with the ZFS file system that runs on the platform and it takes advantage of the so-called parity disk - a specific drive where data located on the other drives is cloned with an additional bit added to it. If one of the disks stops working, your websites shall continue working from the other ones and once we replace the malfunctioning one, the data which will be copied on it will be recovered from what is stored on the rest of the drives as well as the data from the parity disk. This is performed so as to be able to recalculate the bits of each file correctly and to verify the integrity of the information cloned on the new drive. This is an additional level of security for the content you upload to your web hosting account along with the ZFS file system which analyzes a unique digital fingerprint for every single file on all the hard drives in real time.

RAID in Semi-dedicated Hosting

The information uploaded to any semi-dedicated hosting account is stored on SSD drives which operate in RAID-Z. One of the drives in type of a configuration is used for parity - each time data is copied on it, an additional bit is added. In case a disk turns out to be problematic, it will be taken out of the RAID without interrupting the functioning of the sites because the data will load from the remaining drives, and when a new drive is included, the data that will be cloned on it will be a mix between the data on the parity disk and data stored on the other drives in the RAID. That is done so as to guarantee that the data that is being copied is correct, so the moment the new drive is rebuilt, it could be incorporated into the RAID as a production one. This is an additional guarantee for the integrity of your information because the ZFS file system that runs on our cloud web hosting platform analyzes a special checksum of all the copies of the files on the various drives to be able to avoid any possibility of silent data corruption.