RAID, or Redundant Array of Independent Disks, is a technology of keeping data on multiple hard drives which operate together as one single logical unit. The drives can be physical or logical i.e. in the latter case one single drive is split into separate ones using virtualization software. In any case, exactly the same information is saved on all drives and the basic advantage of using this kind of a setup is that in case a drive breaks down, the data shall still be available on the remaining ones. Having a RAID also enhances the performance as the input and output operations will be spread among a few drives. There are several types of RAID depending on how many drives are used, whether writing is carried out on all drives in real time or just on one, and how the data is synced between the drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. All these factors imply that the error tolerance and the performance between the various RAID types could differ.
RAID in Cloud Hosting
The SSD drives that our cutting-edge cloud Internet hosting platform uses for storage function in RAID-Z. This type of RAID is created to work with the ZFS file system that runs on the platform and it works by using the so-called parity disk - a special drive where info saved on the other drives is duplicated with an additional bit added to it. In case one of the disks stops functioning, your websites will continue working from the other ones and as soon as we replace the malfunctioning one, the info that will be cloned on it will be recovered from what is stored on the remaining drives along with the information from the parity disk. This is performed in order to be able to recalculate the bits of every file properly and to verify the integrity of the information cloned on the new drive. This is one more level of security for the information you upload to your cloud hosting account in addition to the ZFS file system that compares a special digital fingerprint for every single file on all hard drives in real time.
RAID in Semi-dedicated Hosting
The SSD drives which are used for holding any content uploaded to the semi-dedicated hosting accounts that we offer operate in RAID-Z. This is a special setup where one or more drives are employed for parity i.e. the system will include an additional bit to any data duplicated on this type of a disk drive. In the event that a disk fails and is substituted with a new one, what information will be duplicated on the latter will be a combination calculated between the data on the other disks and that on the parity one. This is done to guarantee that the information on the new drive will be correct. During the procedure, the RAID will continue functioning normally and the malfunctioning drive won't impact the normal operation of your websites at all. Using SSDs in RAID-Z is an outstanding addition to the ZFS file system which runs on our advanced cloud platform with regards to preserving the integrity of your files since ZFS uses unique digital identifiers named checksums in order to prevent silent data corruption.
RAID in VPS Hosting
The SSD drives which we use on the physical machines where we set up virtual private servers work in RAID to ensure that any content that you upload will be available and intact all of the time. At least 1 drive is used for parity - one bit of information is added to any data cloned on it. If a main drive stops working, it is replaced and the information which will be copied on it is calculated between the remaining drives and the parity one. That’s done to make sure that the correct information is copied and that not a single file is corrupted because the new drive will be a part of the RAID afterwards. We also use hard disk drives operating in RAID on the backup servers, so if you add this upgrade to your VPS plan, you'll use an even more reliable web hosting service as your content will be available on multiple drives irrespective of any type of unforeseen hardware malfunction.