RAID, or Redundant Array of Independent Disks, is a technology for keeping data on several hard disk drives which work together as one logical unit. The drives could be physical or logical i.e. in the latter case a single drive is divided into individual ones using virtualization software. In any case, the same information is stored on all of the drives and the key advantage of employing this type of a setup is that in case a drive breaks down, the data will remain available on the other ones. Using a RAID also boosts the overall performance since the input and output operations will be spread among a number of drives. There are several kinds of RAID dependant upon how many hard disks are used, whether writing is performed on all of the drives in real time or just on a single one, and how the information is synchronized 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 suggest that the error tolerance as well as the performance between the various RAID types can vary.

RAID in Shared Hosting

Our advanced cloud web hosting platform where all shared hosting accounts are created uses super fast SSD drives as an alternative to the classic HDDs, and they work in RAID-Z. With this configuration, multiple hard drives work together and at least one is a dedicated parity disk. Put simply, when data is written on the remaining drives, it is cloned on the parity one adding an extra bit. This is done for redundancy as even if a drive fails or falls out of the RAID for some reason, the information can be rebuilt and verified thanks to the parity disk and the data saved on the other ones, thus nothing will be lost and there won't be any service disorders. This is another level of protection for your info together with the top-notch ZFS file system which uses checksums to make sure that all of the data on our servers is intact and is not silently corrupted.

RAID in Semi-dedicated Servers

The information uploaded to any semi-dedicated server account is saved on SSD drives that work in RAID-Z. One of the drives in type of a configuration is used for parity - whenever data is copied on it, an extra bit is added. If a disk happens to be faulty, it will be removed from the RAID without interrupting the functioning of the websites because the data will load from the rest of the drives, and when a new drive is added, the info which will be duplicated on it will be a blend between the information on the parity disk and data kept on the other drives in the RAID. This is done so as to ensure that the info which is being copied is correct, so once the new drive is rebuilt, it can be integrated into the RAID as a production one. This is an additional guarantee for the integrity of your information since the ZFS file system which runs on our cloud Internet hosting platform analyzes a unique checksum of all of the copies of the files on the different drives so as to avoid any possibility of silent data corruption.