Redundant Array of Independent Disks, or RAID, is a way of keeping content on several hard drives at the same time. A RAID could be software or hardware depending on the HDDs which are used - physical or logical ones, but what’s common between them is that they all operate as just one single unit where data is saved. The top advantage of employing a RAID is redundancy as the information on all the drives is exactly the same at all times, so even in the event that a drive fails for some reason, the info will still be present on the rest of the drives. The overall performance is also enhanced because the reading and writing processes could be split between different drives, so a single one can't be overloaded. There are different kinds of RAIDs where the effectiveness and fault tolerance can vary depending on the specific setup - whether information is written on all the drives real-time or it's written on one drive and after that mirrored on another, what amount of drives are used for the RAID, etc.
RAID in Cloud Hosting
The state-of-the-art cloud web hosting platform where all cloud hosting accounts are generated uses super fast SSD drives rather than the classic HDDs, and they operate in RAID-Z. With this setup, a number of hard drives operate together and at least a single one is a dedicated parity disk. Basically, when data is written on the remaining drives, it is 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 recorded on the other ones, so absolutely nothing will be lost and there won't be any service interruptions. This is another level of security for your data along with the advanced ZFS file system which uses checksums to ensure that all data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Servers
In case you host your websites within a semi-dedicated server account from our company, all of the content that you upload will be stored on SSD drives which operate in RAID-Z. With this form of RAID, at least 1 of the hard disks is used for parity - when data is synchronized between the drives, an extra bit is included in it on the parity one. The reasoning behind this is to guarantee the integrity of the data that is cloned to a new drive in the event that one of the drives in the RAID stops functioning as the website content being copied on the new disk is recalculated from the info on the standard hard drives and on the parity one. An additional advantage of RAID-Z is the fact that even if a hard drive stops functioning, the system can switch to a different one right away without service interruptions of any kind. RAID-Z adds one more level of safety for the content which you upload on our cloud hosting platform along with the ZFS file system which uses unique checksums in order to authenticate the integrity of every single file.
RAID in VPS Servers
The physical servers where we make VPS server employ extremely fast SSD drives that will raise the speed of your websites substantially. The disk drives function in RAID to make sure that you will not lose any data due to a power loss or a hardware malfunction. The production servers use a variety of drives where the information is kept and one disk is used for parity i.e. one bit is added to all data copied on it, that makes it much easier to restore the site content without any loss if a main drive fails. If you take advantage of our backup service, your information will be kept on a separate machine that uses standard hard-disk drives and even though there's no parity one in this case, they are also in a RAID to make sure that we will have a backup of your site content all the time. With this configuration your data will always be safe as it will be available on several disk drives.