RAID, or Redundant Array of Independent Disks, is a technology of storing data on a number hard disk drives which work together as one logical unit. The drives can be physical or logical i.e. in the second case one drive is split into separate ones using virtualization software. In either case, exactly the same info is kept on all the drives and the main benefit of employing this kind of a setup is that if a drive fails, the data will remain available on the remaining ones. Using a RAID also boosts the performance because the input and output operations will be spread among several drives. There are several kinds of RAID dependant upon how many hard disks are used, whether writing is carried out on all the drives in real time or just on a single one, and how the data is synchronized between the hard drives - whether it is recorded in blocks on one drive after another or it is mirrored from one on the others. All these factors mean that the fault tolerance as well as the performance between the various RAID types could differ.
RAID in Hosting
The SSD drives which our cutting-edge cloud web hosting platform employs for storage work in RAID-Z. This kind of RAID is created to work with the ZFS file system that runs on the platform and it works by using the so-called parity disk - a special drive where data stored on the other drives is duplicated with an extra bit added to it. In case one of the disks stops working, your websites will continue working from the other ones and as soon as we replace the malfunctioning one, the info which will be copied on it will be rebuilt from what is stored on the rest of the drives as well as the information from the parity disk. This is performed in order to be able to recalculate the bits of each file adequately and to confirm the integrity of the data cloned on the new drive. This is another level of security for the content you upload to your hosting account together with the ZFS file system that compares a special digital fingerprint for each and every file on all the disk drives in real time.
RAID in Semi-dedicated Hosting
The SSD drives which are used for storing any site content uploaded to the semi-dedicated hosting accounts that we provide work in RAID-Z. This is a specific configuration where one or more disk drives are used for parity i.e. the system will include an additional bit to any data duplicated on such a hard drive. If a disk fails and is substituted with another one, what data will be duplicated on the latter will be a mix calculated between the data on the remaining drives and that on the parity one. This is done to guarantee that the info on the new drive shall be correct. Throughout the procedure, the RAID will continue working normally and the faulty drive won't have an impact on the adequate operation of your Internet sites at all. Using SSDs in RAID-Z is an impressive addition to the ZFS file system that runs on our state-of-the-art cloud platform with regard to preserving the integrity of your files because ZFS uses special digital identifiers identified as checksums in order to avoid silent data corruption.
The physical servers where we create virtual private server work with quick SSD drives which will raise the speed of your Internet sites substantially. The disk drives work in RAID to make sure that you will not lose any data due to a power loss or a hardware breakdown. The production servers take advantage of many different drives where the information is saved and one disk is used for parity i.e. one bit is added to all of the data copied on it, that makes it easier to restore the website content without loss in the event a main drive fails. In case you use our backup service, the info will be stored on an individual machine which uses standard hard-disk drives and although there's no parity one in this case, they are also in a RAID to guarantee that we will have a backup of your site content all of the time. With this configuration your information will always be safe as it will be available on several disk drives.