RAID, or Redundant Array of Independent Disks, is a technology for keeping data on several hard drives that operate together as a single logical unit. The drives could be physical or logical i.e. in the aforementioned case one single drive is divided into different ones via virtualization software. In either case, identical information is saved on all of the drives and the key benefit of employing this kind of a setup is that if a drive fails, the data will remain available on the remaining ones. Employing a RAID also boosts the overall performance as the input and output operations will be spread among several drives. There are several kinds of RAID depending on how many hard drives are used, whether writing is carried out on all of the drives in real time or just on a single one, and how the information is synchronized between the hard drives - whether it is written in blocks on one drive after another or it is mirrored from one on the others. All these factors suggest that the fault tolerance as well as the performance between the various RAID types may differ.
RAID in Cloud Hosting
The hard drives which we use for storage with our top-notch cloud Internet hosting platform are not the traditional HDDs, but extremely fast solid-state drives (SSD). They work in RAID-Z - a special setup developed for the ZFS file system which we use. All of the content that you add to the cloud hosting account will be stored on multiple drives and at least one of them shall be employed as a parity disk. This is a special drive where an extra bit is added to any content copied on it. In the event that a disk in the RAID stops functioning, it'll be replaced without any service disturbances and the data will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the other disks. This is done so as to ensure the integrity of the data and along with the real-time checksum authentication that the ZFS file system executes on all drives, you will never have to be concerned about the loss of any data no matter what.
RAID in Semi-dedicated Servers
The RAID type which we employ for the cloud Internet hosting platform where your semi-dedicated server account will be created is called RAID-Z. What is different about it is that at least one of the disks is used as a parity drive. In simple terms, whenever any kind of data is duplicated on this specific drive, one more bit is included to it and if a malfunctioning disk is changed, the data which will be cloned on it is a combination of the data on the remaining hard disks in the RAID and that on the parity one. This is done to make sure that your info is intact. During this process, your websites will be working normally because RAID-Z enables an entire 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 which uses checksums to ensure that no data will get silently corrupted on our servers, you won't have to worry about the integrity of your files.
RAID in VPS Servers
All VPS server accounts which our company provides are made on physical servers that use SSD drives working in RAID. At least 1 drive is employed for parity - one extra bit is included in the info copied on it and in case a main disk breaks down, this bit makes it easier to recalculate the bits of the files on the damaged drive so that the correct info is restored on the new drive included in the RAID. In the mean time, your websites will still be online as all the information will still load from at least one other disk drive. In the event that you add routine backups to your VPS package, a copy of the information will be kept on standard hard drives that also work in RAID since we would like to make sure that any site content you upload will be safe and sound all of the time. Employing multiple hard disks in RAID for all the main and backup servers enables us to offer fast and reliable hosting service.