Redundant Array of Independent Disks, or RAID, is a method of keeping content on a number of hard disk drives simultaneously. A RAID might be software or hardware depending on the hard drives that are used - physical or logical ones, yet what is common between them is that they all work as just one single unit where information is stored. The main advantage of employing a RAID is redundancy because the info on all the drives is the same all the time, so even in the event that a drive fails for some reason, the information will still be present on the rest of the drives. The overall performance will also improve as the reading and writing processes can be split between multiple drives, so a single one won't be overloaded. There're different kinds of RAIDs where the performance and fault tolerance may differ depending on the specific setup - whether information is written on all the drives in real time or it's written on a single drive and then mirrored on another, the number of drives are used for the RAID, etcetera.
RAID in Website Hosting
The hard disks which we employ for storage with our state-of-the-art cloud web hosting platform are not the traditional HDDs, but fast solid-state drives (SSD). They function in RAID-Z - a special setup developed for the ZFS file system that we use. All of the content that you add to your website hosting account will be saved on multiple hard drives and at least one will be used as a parity disk. This is a specific drive where an extra bit is included to any content copied on it. If a disk in the RAID fails, it will be changed without any service interruptions and the data will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the other disks. This is done so as to guarantee the integrity of the info and along with the real-time checksum validation that the ZFS file system runs on all drives, you will never need to be concerned about losing any information no matter what.
RAID in Semi-dedicated Servers
If you host your websites within a semi-dedicated server account from our company, any content that you upload will be held on SSD drives which operate in RAID-Z. With this form of RAID, at least one of the hard drives is employed for parity - when data is synced between the drives, an additional bit is added to it on the parity one. The idea behind this is to guarantee the integrity of the information that is cloned to a new drive if one of the disks in the RAID stops working since the site content being copied on the new disk is recalculated from the info on the standard disk drives and on the parity one. An additional advantage of RAID-Z is that even if a disk drive stops functioning, the system can easily switch to a different one immediately without service disturbances of any type. RAID-Z adds an extra level of safety for the content which you upload on our cloud Internet hosting platform together with the ZFS file system that uses unique checksums so as to validate the integrity of every single file.
RAID in VPS Servers
The physical servers where we create VPS server use super fast SSD drives that will increase the speed of your Internet sites considerably. The hard drives function in RAID to make sure that you will not lose any information because of a power loss or a hardware breakdown. The production servers take advantage of multiple drives where the data is kept and one disk is used for parity i.e. one bit is added to all the data copied on it, that makes it much easier to recover the website content without loss in case a main drive breaks down. If you take advantage of our backup service, your data will be saved on an individual machine that uses standard hard-disk drives and although there isn't a parity one in this case, they are also in a RAID to make sure that we will have a backup of your content all the time. With this kind of configuration your data will always be safe because it will be available on a lot of drives.