RAID, or Redundant Array of Independent Disks, is a technology of storing data on several hard disks that function together as one single logical unit. The drives can be physical or logical i.e. in the second case one drive is divided into different ones via virtualization software. In any case, the same information is kept on all of the drives and the basic advantage of employing this type of a setup is that in case a drive fails, the data will remain available on the remaining ones. Employing a RAID also boosts the performance since the input and output operations will be spread among a couple of drives. There are several kinds of RAID dependant upon how many drives are used, whether writing is done on all the drives in real time or just on one, and how the information is synced between the drives - whether it is written in blocks on one drive after another or it is mirrored from one on the others. All these factors show that the fault tolerance as well as the performance between the various RAID types can vary.
RAID in Hosting
The SSD drives which our cutting-edge cloud hosting platform employs for storage function in RAID-Z. This type of RAID is created to work with the ZFS file system which runs on the platform and it employs the so-called parity disk - a special drive where information saved on the other drives is copied with an additional bit added to it. In case one of the disks stops functioning, your sites will continue working from the other ones and after we replace the problematic one, the information that will be duplicated on it will be rebuilt from what is stored on the other drives together with the info from the parity disk. This is performed so as to be able to recalculate the elements of every file correctly and to authenticate the integrity of the information copied on the new drive. This is an additional level of security for the content you upload to your hosting account in addition to the ZFS file system that analyzes a unique digital fingerprint for every single file on all of the disk drives in real time.
RAID in Semi-dedicated Hosting
The info uploaded to any semi-dedicated hosting account is kept on SSD drives that operate in RAID-Z. One of the drives in this kind of a configuration is used for parity - any time data is copied on it, an extra bit is added. In case a disk turns out to be flawed, it will be taken out of the RAID without disturbing the functioning of the websites since the data will load from the other drives, and when a new drive is included, the info that will be duplicated on it will be a blend between the information on the parity disk and data kept on the other hard drives in the RAID. That is done so as to guarantee that the information that is being cloned is correct, so once the new drive is rebuilt, it could be integrated into the RAID as a production one. This is an additional warranty for the integrity of your info because the ZFS file system that runs on our cloud hosting platform compares a special checksum of all of the copies of your files on the various drives to be able to avoid any possibility of silent data corruption.
RAID in VPS Web Hosting
The physical servers where we make virtual private server use super fast SSD drives that will raise the speed of your websites noticeably. The hard disks function in RAID to guarantee that you won't lose any info as a result of a power loss or a hardware breakdown. The production servers employ multiple drives where the information is stored and one disk is used for parity i.e. one bit is added to all info copied on it, that makes it easier to restore the site content without any loss in case a main drive fails. In case you take advantage of our backup service, your information will be stored on a separate machine which uses standard hard-disk drives and even though there isn't a parity one in this case, they are also in a RAID to ensure that we will have a backup copy of your site content all the time. With this kind of configuration your info will always be safe as it will be available on multiple disk drives.