Redundant Array of Independent Disks, or RAID, is a method of saving content on several hard disks at the same time. A RAID might be software or hardware depending on the HDDs that are used - physical or logical ones, yet what is common between them is that they all work as just a single unit where your information is stored. The biggest advantage of using a RAID is redundancy because the info on all the drives will be the same all of the time, so even in case one of the drives fails for whatever reason, the data will still be available on the remaining drives. The general performance is also better since the reading and writing processes will be split between a number of drives, so a single one will never be overloaded. There're different sorts of RAIDs where the effectiveness and fault tolerance may differ depending on the specific setup - whether info is written on all the drives in real time or it is written on a single drive and after that mirrored on another, the number of drives are used for the RAID, etc.
RAID in Shared Hosting
Any content that you upload to your new shared hosting account will be stored on fast SSD drives which operate in RAID-Z. This setup is built to work with the ZFS file system that runs on our cloud web hosting platform and it adds an additional level of security for your site content in addition to the real-time checksum validation which ZFS uses to ensure the integrity of the data. With RAID-Z, the information is stored on a couple of disks and at least one is a parity disk - whenever information is recorded on it, an extra bit is added, so in case any drive stops functioning for whatever reason, the stability of the data can be verified by recalculating its bits based on what is kept on the production hard disks and on the parity one. With RAID-Z, the functioning of our system will not be interrupted and it will continue operating efficiently until the problematic drive is changed and the information is synchronized on it.
RAID in Semi-dedicated Hosting
The RAID type that we use for the cloud hosting platform where your semi-dedicated hosting account shall be created is named RAID-Z. What's different about it is that at least 1 of the disks is used as a parity drive. Put simply, whenever any data is copied on this special drive, one more bit is added to it and in the event that a faulty disk is changed, the information which will be copied on it is a combination of the data on the other drives in the RAID and that on the parity one. We do this to guarantee that your data is intact. During this process, your sites will be functioning normally since RAID-Z makes it possible for a whole drive to fail without service disruptions and it simply uses one of the remaining ones as the main production drive. Employing RAID-Z together with the ZFS file system that uses checksums to ensure that no data will get silently corrupted on our servers, you won't need to worry about the integrity of your files.
RAID in VPS Web Hosting
The SSD drives that we use on the physical machines where we generate virtual private servers work in RAID to ensure that any content that you upload will be available and intact at all times. At least one drive is used for parity - one bit of info is added to any data cloned on it. If a main drive stops working, it is changed and the information which will be cloned on it is calculated between the other drives and the parity one. It's done this way to make sure that the required info is copied and that not a single file is corrupted as the new drive will be a part of the RAID afterwards. Also, we use hard disk drives functioning in RAID on the backup servers, so in the event that you add this upgrade to your VPS package, you'll use an even more reliable Internet hosting service as your content will be available on multiple drives regardless of any sort of unforeseen hardware malfunction.