RAID, or Redundant Array of Independent Disks, is a technology of storing data on multiple hard disks which work together as a single logical unit. The drives could be physical or logical i.e. in the aforementioned case a single drive is split into separate ones using virtualization software. Either way, exactly the same data is saved on all the drives and the key advantage of using this type of a setup is that in the event that a drive fails, the data will still be available on the remaining ones. Using a RAID also improves the overall performance because the input and output operations will be spread among several drives. There are several types of RAID dependant upon how many drives are used, whether writing is carried out on all drives in real time or just on one, and how the info is synced between the hard drives - whether it is recorded in blocks on one drive after another or it is mirrored from one on the others. These factors mean that the error tolerance as well as the performance between the different RAID types can vary.
RAID in Hosting
The drives that we use for storage with our ground-breaking cloud hosting platform are not the standard HDDs, but fast solid-state drives (SSD). They operate in RAID-Z - a special setup designed for the ZFS file system that we work with. Any content that you upload to your hosting account will be kept on multiple disk drives and at least 1 shall be used as a parity disk. This is a specific drive where an additional bit is included to any content copied on it. In case a disk in the RAID fails, it'll be changed without any service interruptions and the info will be recovered on the new drive by recalculating its bits using the data on the parity disk along with that on the other disks. This is done in order to ensure the integrity of the information and together with the real-time checksum validation which the ZFS file system executes on all drives, you will never need to be concerned about the loss of any data no matter what.
RAID in Semi-dedicated Hosting
The SSD drives which are used for holding any content uploaded to the semi-dedicated hosting accounts which we provide function in RAID-Z. This is a special configuration where one or more drives are employed for parity i.e. the system will include an additional bit to any data duplicated on such a hard drive. If a disk fails and is replaced with another one, what data will be duplicated on the latter shall be a mix calculated between the data on the other hard disks and that on the parity one. This is done to guarantee that the information on the new drive shall be correct. During the process, the RAID will continue operating adequately and the malfunctioning drive won't affect the normal operation of your websites by any means. Using SSDs in RAID-Z is an excellent addition to the ZFS file system which runs on our advanced cloud platform in terms of preserving the integrity of your files since ZFS uses special digital identifiers known as checksums so as to avoid silent data corruption.
All virtual private server accounts that our company offers are created on physical servers that take advantage of SSD drives working in RAID. At least 1 drive is used for parity - one additional bit is added to the info duplicated on it and if a main disk stops working, this bit makes it much simpler to recalculate the bits of the files on the failed disk drive so that the accurate data is restored on the new drive added to the RAID. Meanwhile, your websites will still be online since all the data will still load from at least one more hard drive. In case you add regular backups to your VPS plan, a copy of the data will be stored on standard hard drives which also function in RAID as we would like to make sure that any type of content you add will be safe and sound all the time. Using multiple drives in RAID for all of the main and backup servers allows us to offer fast and reliable Internet hosting service.