Redundant Array of Independent Disks, or RAID, is a method of storing content on several hard disk drives concurrently. A RAID could be software or hardware depending on the HDDs that are used - physical or logical ones, however what is common between them is that they all work as just a single unit where information is stored. The biggest advantage of using a RAID is redundancy since the data on all of the drives is the same all the time, so even in case some drive fails for whatever reason, the data will still be available on the rest of the drives. The overall performance is also better as the reading and writing processes will be split between different drives, so a single one will not be overloaded. There are different types of RAIDs where the capabilities and fault tolerance can vary depending on the exact setup - whether data is written on all of the drives in real time or it is written on one drive and afterwards mirrored on another, what number of drives are used for the RAID, and so on.
RAID in Web Hosting
The SSD drives which our cutting-edge cloud hosting platform uses for storage operate in RAID-Z. This type of RAID is designed to work with the ZFS file system which runs on the platform and it uses the so-called parity disk - a specific drive where information saved on the other drives is cloned with an additional bit added to it. If one of the disks stops working, your sites will continue working from the other ones and as soon as we replace the problematic one, the info which will be copied on it will be rebuilt from what is stored on the other drives as well as the info from the parity disk. This is done so as to be able to recalculate the elements of each file correctly and to validate the integrity of the data duplicated on the new drive. This is one more level of security for the content you upload to your web hosting account in addition to the ZFS file system which analyzes a special digital fingerprint for every single file on all of the disk drives in real time.
RAID in Semi-dedicated Servers
The information uploaded to any semi-dedicated server account is saved on SSD drives which work 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 faulty, it will be removed from the RAID without interrupting the work of the websites as the data will load from the other drives, and when a new drive is added, the info that will be duplicated on it will be a combination between the data on the parity disk and data saved on the other hard drives in the RAID. This is done in order to ensure that the info which is being duplicated is accurate, so once the new drive is rebuilt, it could be included in the RAID as a production one. This is an extra guarantee for the integrity of your data because the ZFS file system which runs on our cloud Internet hosting platform compares a unique checksum of all the copies of the files on the different drives so as to avoid any possibility of silent data corruption.
RAID in VPS Servers
If you use one of our VPS server solutions, any content which you upload will be kept on SSD drives that operate in RAID. At least one drive is used for parity to ensure the integrity of your information. In simple terms, this is a special drive where information is copied with one bit added to it. If a disk part of the RAID stops functioning, your sites will continue working and when a new disk replaces the faulty one, the bits of the information that will be duplicated on it are calculated by using the healthy and the parity drives. By doing this, any chance of corrupting data during the process is prevented. We also employ standard hard disks which operate in RAID for storing backups, so in case you add this service to your VPS plan, your content will be kept on multiple drives and you won't ever need to worry about its integrity even in the event of multiple drive breakdowns.