RAID, or Redundant Array of Independent Disks, is a technology of storing data on several hard disks that operate together as one single logical unit. The drives could be physical or logical i.e. in the second case a single drive is split into independent ones via virtualization software. In either case, identical information is saved on all of the drives and the key benefit of using this kind of a setup is that in case a drive fails, the data will still be available on the other ones. Employing a RAID also boosts the overall performance as the input and output operations will be spread among a number of drives. There are several types of RAID dependant upon how many hard disks are used, whether writing is performed on all the drives in real time or just on a single one, and how the info is synchronized between the drives - whether it's recorded in blocks on one drive after another or it is mirrored from one on the others. All of these factors show that the error tolerance and the performance between the various RAID types could differ.
RAID in Shared Hosting
The drives which we use for storage with our revolutionary cloud hosting platform are not the traditional HDDs, but high-speed NVMes. They operate in RAID-Z - a special setup designed for the ZFS file system that we work with. All of the content that you upload to the shared hosting account will be kept on multiple drives and at least one of them shall be employed as a parity disk. This is a special drive where a further bit is added to any content copied on it. In the event that a disk in the RAID stops working, it will be changed with no service interruptions and the data will be recovered on the new drive by recalculating its bits thanks to the data on the parity disk along with that on the remaining disks. This is done to guarantee the integrity of the data and together with the real-time checksum validation that the ZFS file system runs on all drives, you will never have to concern yourself with the loss of any info no matter what.
RAID in Semi-dedicated Servers
The RAID type that we employ for the cloud web hosting platform where your semi-dedicated server account will be created is named RAID-Z. What's different about it is that at least one of the disks is employed as a parity drive. In simple terms, whenever any data is duplicated on this specific hard drive, one more bit is included to it and if a defective disk is replaced, the info that will be cloned on it is a combination of the data on the remaining drives in the RAID and that on the parity one. This is done to guarantee that your information is intact. During this process, your sites will be up and running normally as RAID-Z allows for an entire drive to fail without service disturbances and it simply works by using one of the remaining ones as the main production drive. Using RAID-Z together with the ZFS file system that uses checksums to warrant that no data shall get silently corrupted on our servers, you will never need to worry about the integrity of your files.
RAID in VPS Servers
All VPS server accounts which our company offers are made on physical servers that take advantage of NVMe drives operating in RAID. At least 1 drive is used for parity - one extra bit is included in the info duplicated on it and if a main disk breaks down, this bit makes it much simpler to recalculate the bits of the files on the damaged disk drive so that the right info is recovered on the new drive added to the RAID. Meanwhile, your websites will still be online since all the information will still load from at least 1 more disk drive. In case you add routine backups to your VPS plan, a copy of the info will be saved on standard hard disks that also work in RAID as we want to make certain that any sort of website content you add will be protected all the time. Working with multiple hard drives in RAID for all main and backup servers allows us to offer fast and reliable web hosting service.