RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that makes it possible for a system to employ a number of hard drives as one single logical unit. To put it differently, all the drives are used as one and the info on all of them is identical. This kind of a configuration has 2 huge advantages over using a single drive to keep data - the first is redundancy, so in case one drive stops working, the information will be accessible from the others, and the second one is better performance as the input/output, or reading/writing operations will be spread among multiple drives. You can find different RAID types depending on what amount of drives are employed, whether reading and writing are both done from all of the drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, and so on. Determined by the exact setup, the error tolerance and the performance could differ.
RAID in Cloud Website Hosting
The state-of-the-art cloud Internet hosting platform where all cloud website hosting accounts are made uses fast SSD drives as an alternative to the classic HDDs, and they work in RAID-Z. With this configuration, several hard drives work together and at least a single one is a dedicated parity disk. Basically, when data is written on the remaining drives, it is cloned on the parity one adding an extra bit. This is performed for redundancy as even in case some 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 recorded on the other ones, therefore not a thing will be lost and there won't be any service disorders. This is one more level of protection for your information together with the advanced ZFS file system that uses checksums to make sure that all the data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Hosting
The SSD drives that are used for saving any content uploaded to the semi-dedicated hosting accounts that we provide work in RAID-Z. This is a special configuration where one or more hard drives are employed for parity i.e. the system will add an additional bit to any data duplicated on such a disk drive. In case that a disk fails and is replaced with a new one, what information will be duplicated on the latter will be a combination calculated between the data on the other hard disks and that on the parity one. This is done to ensure that the information on the new drive will be correct. Throughout the procedure, the RAID will continue operating normally and the problematic drive won't affect the adequate operation of your websites in any way. Using SSDs in RAID-Z is a great addition to the ZFS file system which runs on our cutting-edge cloud platform with regard to preserving the integrity of your files as ZFS uses unique digital identifiers named checksums so as to avoid silent data corruption.
RAID in VPS
The SSD drives that we use on the physical machines where we generate virtual private servers operate in RAID to make sure that any content which you upload will be available and intact all of the time. At least a single drive is used for parity - one bit of info is added to any data copied on it. In case a main drive fails, it is replaced and the information that will be cloned on it is calculated between the other drives and the parity one. It's done this way to ensure that the correct data is copied and that not a single file is corrupted because the new drive will be used in the RAID afterwards. Also, we use hard drives operating in RAID on the backup servers, so in the event that you add this upgrade to your VPS plan, you shall use an even more reliable hosting service since your content will be available on multiple drives irrespective of any unpredicted hardware failure.