RAID, or Redundant Array of Independent Disks, is a technology of saving data on several hard disks that operate together as one logical unit. The drives can be physical or logical i.e. in the aforementioned case one single drive is divided into independent ones via virtualization software. Either way, the same information is stored on all drives and the main benefit of employing this kind of a setup is that in the event that a drive stops working, the data will still be available on the remaining ones. Employing a RAID also improves the performance since the input and output operations will be spread among several drives. There are several kinds of RAID dependant upon how many drives are used, whether writing is done on all of the drives in real time or just on one, and how the info is synced 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 of these factors imply that the error tolerance and the performance between the different RAID types can differ.
RAID in Shared Web Hosting
The hard drives which we use for storage with our state-of-the-art cloud web hosting platform are not the classic HDDs, but extremely fast solid-state drives (SSD). They work in RAID-Z - a special setup intended for the ZFS file system which we work with. All the content that you upload to the shared web hosting account will be saved on multiple hard drives and at least one of them will be employed as a parity disk. This is a specific drive where an extra bit is added to any content copied on it. If a disk in the RAID fails, it will be replaced with no service disturbances and the info will be recovered on the new drive by recalculating its bits using the data on the parity disk along with that on the remaining disks. This is done in order to guarantee the integrity of the info and along with the real-time checksum verification that the ZFS file system executes on all drives, you will never need to concern yourself with losing any data no matter what.
RAID in Semi-dedicated Servers
The SSD drives that are used for keeping any content uploaded to the semi-dedicated server accounts that we offer operate in RAID-Z. This is a specific configuration where one or more disk drives are employed for parity i.e. the system will include an additional bit to any data copied on this type of a disk drive. In case that a disk fails and is substituted with another one, what data will be copied on the latter shall be a mix calculated between the data on the remaining disks and that on the parity one. This is done to ensure that the data on the new drive shall be accurate. Throughout the procedure, the RAID will continue working adequately and the faulty drive will not have an impact on the proper operation of your sites in any way. Working with SSDs in RAID-Z is a superb addition to the ZFS file system that runs on our revolutionary cloud platform in terms of preserving the integrity of your files since ZFS uses unique digital identifiers referred to as checksums to prevent silent data corruption.
RAID in VPS Servers
The SSD drives which we use on the physical machines where we generate VPS servers operate in RAID to ensure that any content that you upload will be available and intact all the time. At least one drive is employed for parity - one bit of information is added to any data cloned on it. If a main drive stops working, it is replaced and the info which will be duplicated on it is calculated between the rest of the drives and the parity one. That’s done to make sure that the required data is copied and that no file is corrupted because the new drive will be included in the RAID afterwards. We also use hard disk drives operating in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you shall use an even more reliable hosting service as your content will be available on multiple drives regardless of any kind of sudden hardware failure.