RAID, or Redundant Array of Independent Disks, is a technology for keeping data on several hard disk drives which operate together as a single logical unit. The drives can be physical or logical i.e. in the latter case one single drive is split into individual ones via virtualization software. Either way, the very same info is stored on all the drives and the main advantage of employing such a setup is that if a drive stops working, the data shall still be available on the other ones. Having a RAID also enhances the performance since the input and output operations will be spread among a number of drives. There are several types of RAID depending on how many hard drives are used, whether writing is performed on all of the drives in real time or just on one, and how the data is synced between the hard drives - whether it's written in blocks on one drive after another or all of 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 can differ.
RAID in Hosting
The SSD drives that our cutting-edge cloud hosting platform uses for storage function in RAID-Z. This sort 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 extra bit added to it. If one of the disks fails, your Internet sites shall continue working from the other ones and after we replace the malfunctioning one, the information which will be duplicated on it will be rebuilt from what is stored on the rest of the drives together with the information from the parity disk. This is performed in order to be able to recalculate the bits of every file correctly and to validate the integrity of the info cloned on the new drive. This is another level of security for the information you upload to your hosting account in addition to 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
In case you host your sites inside a semi-dedicated hosting account from our firm, all of the content that you upload will be held on SSD drives which operate in RAID-Z. With this type of RAID, at least 1 of the drives is used for parity - when data is synced between the disks, an extra bit is included in it on the parity one. The reasoning behind this is to ensure the integrity of the info which is copied to a new drive if one of the drives in the RAID stops working since the website content being copied on the brand new disk is recalculated from the data on the standard drives and on the parity one. An additional advantage of RAID-Z is the fact that even in the event that a disk drive stops functioning, the system can switch to a different one quickly without service disturbances of any sort. RAID-Z adds an extra level of protection for the content that you upload on our cloud web hosting platform in addition to the ZFS file system that uses unique checksums as a way to verify the integrity of each file.