RAID, or Redundant Array of Independent Disks, is a technology for storing data on several hard disk drives that work together as one logical unit. The drives can be physical or logical i.e. in the latter case one single drive is divided into individual ones through virtualization software. Either way, the same data is saved on all drives and the basic advantage of using this kind of a setup is that if a drive breaks down, the data shall still be available on the remaining ones. Having a RAID also improves the performance as the input and output operations will be spread among a few drives. There are several kinds of RAID dependant upon how many drives are used, whether writing is carried out on all drives in real time or just on one, and how the data is synced 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. These factors show that the error tolerance as well as the performance between the different RAID types can vary.
RAID in Web Hosting
Our cutting-edge cloud web hosting platform where all web hosting
accounts are created employs quick SSD drives as opposed to the standard HDDs, and they function in RAID-Z. With this configuration, a number of hard disks work together and at least one of them is a dedicated parity disk. Put simply, when data is written on the rest of the drives, it is copied on the parity one adding an extra bit. This is done for redundancy as even in case some drive fails or falls out of the RAID for whatever reason, the information can be rebuilt and verified thanks to the parity disk and the data saved on the other ones, which means that absolutely nothing will be lost and there will not be any service interruptions. This is an additional level of security for your info in addition to the state-of-the-art ZFS file system which uses checksums to ensure that all data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Servers
If you host your Internet sites in a semi-dedicated server
account from our company, all the content which you upload will be kept on SSD drives that work in RAID-Z. With this kind of RAID, at least one of the drives is used for parity - when data is synced between the hard drives, an extra bit is added to it on the parity one. The idea behind this is to guarantee the integrity of the data that is copied to a brand new drive in case one of the drives in the RAID stops functioning since the content being copied on the new disk is recalculated from the information on the standard hard drives and on the parity one. Another advantage of RAID-Z is that even if a disk drive stops working, the system can easily switch to a different one right away without service disturbances of any type. RAID-Z adds an extra level of safety for the content which you upload on our cloud hosting platform along with the ZFS file system which uses unique checksums in order to verify the integrity of every single file.