RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which makes it possible for a system to take advantage of a number of hard drives as one single logical unit. To put it differently, all the drives are used as one and the data on all of them is the same. This type of a configuration has 2 huge advantages over using just a single drive to keep data - the first is redundancy, so in case one drive breaks down, the data will be accessible from the others, and the second one is better performance since the input/output, or reading/writing operations will be spread among several drives. There're different RAID types depending on the number of drives are used, if reading and writing are both executed from all drives concurrently, if data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Based on the exact setup, the error tolerance and the performance vary.
RAID in Shared Hosting
Our revolutionary cloud hosting platform where all shared hosting accounts are created uses quick SSD drives rather than the standard HDDs, and they work in RAID-Z. With this configuration, multiple hard drives function together and at least one is a dedicated parity disk. Simply put, when data is written on the other drives, it is copied 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 data can be rebuilt and verified thanks to the parity disk and the data recorded on the other ones, therefore not a single thing will be lost and there will be no service interruptions. This is another level of security for your data together with the advanced ZFS file system which uses checksums to guarantee that all data on our servers is undamaged and is not silently corrupted.
RAID in Semi-dedicated Hosting
The SSD drives that are used for keeping any site 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 include an additional bit to any data cloned on such a hard drive. In the event that a disk fails and is replaced with a new one, what information will be cloned on the latter will be a mix calculated between the data on the remaining hard disks and that on the parity one. This is done to guarantee 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 normal operation of your Internet sites in any respect. Working with SSDs in RAID-Z is an impressive addition to the ZFS file system which runs on our state-of-the-art cloud platform with regard to preserving the integrity of your files as ZFS uses specific digital identifiers named checksums so as to avoid silent data corruption.
RAID in VPS Hosting
The SSD drives that we use on the physical machines where we set up virtual private servers work in RAID to make sure that any content you upload will be available and intact at all times. At least 1 drive is used for parity - one bit of information is added to any data copied on it. If a main drive fails, it is replaced and the information which will be duplicated on it is calculated between the remaining drives and the parity one. This is done to make sure that the needed information is copied and that no file is corrupted since the new drive will be a part of the RAID afterwards. Also, we use hard drives working in RAID on the backup servers, so in the event that you add this upgrade to your VPS package, you shall use an even more reliable hosting service since your content will be available on multiple drives regardless of any type of sudden hardware failure.