RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which allows a system to take advantage of a number of hard drives as one single logical unit. Put simply, all the drives are used as one and the data on all of them is the same. Such a configuration has 2 key advantages over using a single drive to store data - the first one is redundancy, so in case one drive stops working, the data will be accessible from the others, and the second is better performance as the input/output, or reading/writing operations will be distributed among multiple drives. There are different RAID types based on what number of drives are employed, if reading and writing are both done from all the drives at the same time, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Determined by the particular setup, the fault tolerance and the performance could differ.
RAID in Hosting
Our state-of-the-art cloud web hosting platform where all hosting accounts are generated employs quick SSD drives as an alternative to the traditional HDDs, and they function in RAID-Z. With this setup, a number of hard disk drives operate together and at least one of them is a dedicated parity disk. Basically, when data is written on the other drives, it's copied on the parity one adding an extra bit. This is done for redundancy as even if some drive fails or falls out of the RAID for some reason, the info can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, so not a single thing will be lost and there won't be any service disorders. This is another level of security for your information in addition to the state-of-the-art ZFS file system that uses checksums to guarantee that all of the data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Servers
The data uploaded to any semi-dedicated server account is stored on SSD drives that function in RAID-Z. One of the drives in such a setup is used for parity - whenever data is cloned on it, an additional bit is added. In case a disk happens to be defective, it will be removed from the RAID without disturbing the functioning of the Internet sites as the data will load from the rest of the drives, and when a new drive is included, the data that will be duplicated on it will be a blend between the data on the parity disk and data saved on the other hard disks in the RAID. That is done in order to guarantee that the info which is being copied is correct, so the moment the new drive is rebuilt, it could be integrated into the RAID as a production one. This is one more guarantee for the integrity of your info as the ZFS file system which runs on our cloud web hosting platform analyzes a unique checksum of all copies of the files on the various drives in order to avoid any chance of silent data corruption.
RAID in VPS Servers
All VPS server accounts which our company provides are generated on physical servers which take advantage of SSD drives working in RAID. At least one drive is used for parity - one additional bit is included in the info duplicated on it and if a main disk fails, this bit makes it simpler to recalculate the bits of the files on the failed hard disk so that the correct information is restored on the new drive included in the RAID. In the mean time, your sites will stay online because all the data will still load from at least one more hard disk. In case you add routine backups to your VPS package, a copy of your info will be stored on standard hard drives that also work in RAID because we want to make certain that any kind of content you add will be protected all of the time. Using multiple hard drives in RAID for all of the main and backup servers enables us to offer fast and reliable hosting service.