RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to employ a number of hard drives as one single logical unit. In other words, all the drives are used as one and the information on all of them is the same. Such a configuration has 2 major advantages over using a single drive to save data - the first one is redundancy, so if one drive stops working, the data will be accessible through the others, and the second one is improved performance as 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 done from all of the drives simultaneously, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, and many others. Depending on the particular setup, the fault tolerance and the performance could differ.
RAID in Web Hosting
All content which you upload to your new web hosting account will be saved on fast SSD drives which function in RAID-Z. This setup is built to work with the ZFS file system that runs on our cloud Internet hosting platform and it adds one more level of protection for your website content in addition to the real-time checksum verification which ZFS uses to ensure the integrity of the data. With RAID-Z, the info is stored on a couple of disks and at least one is a parity disk - whenever info is recorded on it, an extra bit is added, so if any drive stops working for some reason, the stability of the information can be verified by recalculating its bits based on what is kept on the production disks and on the parity one. With RAID-Z, the functioning of our system will never be interrupted and it will continue operating flawlessly until the malfunctioning drive is changed and the information is synced on it.
RAID in Semi-dedicated Servers
The SSD drives which are used for holding any site content uploaded to the semi-dedicated server accounts which we provide work in RAID-Z. This is a special setup where one or more drives are employed for parity i.e. the system will include an extra bit to any data duplicated on this kind of a drive. In case that a disk fails and is replaced with a new one, what information will be copied on the latter shall be a combination calculated between the data on the other drives and that on the parity one. This is done to ensure that the data on the new drive shall be accurate. Throughout the process, the RAID will continue working adequately and the malfunctioning drive will not impact the normal operation of your sites in any way. Working with SSDs in RAID-Z is an excellent addition to the ZFS file system that runs on our state-of-the-art cloud platform with regard to preserving the integrity of your files because ZFS uses unique digital identifiers referred to as checksums in order to avoid silent data corruption.
RAID in VPS Servers
The SSD drives that we use on the machines where we set up VPS servers work in RAID to make sure that any content that you upload will be available and intact all the time. At least 1 drive is used for parity - one bit of information is added to any data cloned on it. If a main drive fails, it is replaced and the info that will be cloned on it is calculated between the remaining drives and the parity one. That’s done to make sure that the required data is copied and that no file is corrupted as the new drive will be incorporated into the RAID afterwards. Also, we use hard drives operating in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you'll use an even more reliable web hosting service since your content will be available on multiple drives irrespective of any kind of unexpected hardware failure.