Redundant Array of Independent Disks, or RAID, is a way of storing content on multiple hard disks concurrently. A RAID could be software or hardware based on the drives which are used - physical or logical ones, however what’s common between them is that they all function as just a single unit where information is saved. The key advantage of employing a RAID is redundancy as the info on all of the drives is identical all the time, so even in the event that some drive fails for some reason, the information will still be present on the remaining drives. The overall performance will also improve because the reading and writing processes will be split between multiple drives, so a single one will never be overloaded. There are different types of RAIDs where the functionality and fault tolerance may vary according to the exact setup - whether your data is written on all of the drives in real time or it's written on a single drive and then mirrored on another, what amount of drives are used for the RAID, etc.
RAID in Shared Hosting
The SSD drives which our cutting-edge cloud hosting platform uses for storage work in RAID-Z. This type of RAID is intended to work with the ZFS file system that runs on the platform and it employs the so-called parity disk - a special drive where info saved on the other drives is cloned with an extra bit added to it. In the event that one of the disks stops working, your Internet sites will continue working from the other ones and once we replace the bad one, the info that will be cloned on it will be recovered from what is stored on the rest of the drives as well as the information from the parity disk. This is done in order to be able to recalculate the elements of each and every file adequately and to authenticate the integrity of the information cloned on the new drive. This is one more level of security for the content you upload to your shared hosting account in addition to the ZFS file system which analyzes a unique digital fingerprint for each and every file on all of the drives in real time.
RAID in Semi-dedicated Hosting
The RAID type that we use for the cloud Internet hosting platform where your semi-dedicated hosting account will be created is called RAID-Z. What's different about it is that at least 1 of the disks is used as a parity drive. In simple terms, whenever any data is duplicated on this particular hard drive, one more bit is added to it and in the event that a defective disk is changed, the info that will be copied on it is a combination of the data on the remaining hard disks in the RAID and that on the parity one. We do this to guarantee that the info is intact. During this process, your sites will be up and running normally since RAID-Z enables an entire drive to fail without service interruptions and it simply uses one of the other ones as the main production drive. Using RAID-Z together with the ZFS file system that uses checksums to guarantee that no data can get silently corrupted on our servers, you won't have to worry about the integrity of your files.
The physical servers where we create virtual private server work with extremely fast SSD drives that will increase the speed of your sites substantially. The drives work in RAID to guarantee that you will not lose any info due to a power loss or a hardware breakdown. The production servers take advantage of a variety of drives where the data is kept and one disk is used for parity i.e. one bit is added to all of the information copied on it, which makes it easier to restore the site content without loss in case a main drive stops working. If you choose our backup service, your data will be kept on an individual machine that uses standard hard-disk drives and although there's no parity one in this case, they are also in a RAID to make sure that we will have a backup copy of your content all of the time. With this setup your data will always be safe as it will be available on a lot of disk drives.