RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to employ many hard drives as a single logical unit. In other words, all drives are used as one and the information on all of them is identical. This type of a configuration has two huge advantages over using just a single drive to keep data - the first is redundancy, so in the event that one drive breaks down, the data will be accessible through the others, and the second is better performance because the input/output, or reading/writing operations will be distributed among several drives. There're different RAID types depending on how many drives are employed, if reading and writing are both done from all drives at the same time, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and so on. Depending on the exact setup, the fault tolerance and the performance may differ.
RAID in Shared Web Hosting
The SSD drives which our cutting-edge cloud Internet hosting platform employs for storage function in RAID-Z. This type of RAID is designed to work with the ZFS file system which runs on the platform and it takes advantage of the so-called parity disk - a specific drive where info kept on the other drives is cloned with an extra bit added to it. In the event that one of the disks stops working, your websites will continue working from the other ones and after we replace the problematic one, the info that will be duplicated on it will be rebuilt from what is stored on the other drives along with 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 verify the integrity of the data copied on the new drive. This is an additional level of security for the content which you upload to your shared web hosting account along with the ZFS file system which analyzes a special digital fingerprint for each file on all the disk drives in real time.
RAID in Semi-dedicated Hosting
The data uploaded to any semi-dedicated hosting account is saved on SSD drives which work in RAID-Z. One of the drives in type of a setup is used for parity - any time data is cloned on it, an extra bit is added. If a disk turns out to be defective, it will be removed from the RAID without disturbing the operation of the websites since the data will load from the rest of the drives, and when a brand new drive is included, the information that will be copied on it will be a blend between the information on the parity disk and data stored on the other hard drives in the RAID. That is done in order to guarantee that the data which is being cloned is accurate, so as soon as the new drive is rebuilt, it can be included in the RAID as a production one. This is one more warranty for the integrity of your information since the ZFS file system which runs on our cloud Internet hosting platform compares a special checksum of all copies of the files on the different drives to avoid any possibility of silent data corruption.
All virtual private server accounts that our company provides are created on physical servers that employ SSD drives functioning in RAID. At least 1 drive is used for parity - one additional bit is added to the info cloned on it and in case a main disk fails, this bit makes it easier to recalculate the bits of the files on the failed hard disk so that the accurate info is restored on the new drive included in the RAID. In the mean time, your sites will still be online because all the information will still load from at least one more disk drive. In the event that you add regular backups to your VPS plan, a copy of the information will be stored on standard hard disks that also work in RAID since we want to make sure that any sort of website content you upload will be safe and sound all of the time. Using multiple hard drives in RAID for all the main and backup servers enables us to offer fast and reliable web hosting service.