RAID, or Redundant Array of Independent Disks, is a technology for saving data on multiple hard disks that work together as a single logical unit. The drives could be physical or logical i.e. in the second case one single drive is split into separate ones through virtualization software. In any case, identical information is saved on all the drives and the basic benefit of employing such a setup is that if a drive stops working, the data shall still be available on the other ones. Having a RAID also enhances the performance since the input and output operations will be spread among a couple of drives. There are several types of RAID dependant upon how many hard disks are used, whether writing is carried out on all drives in real time or just on a single one, and how the data is synced between the hard drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. All these factors suggest that the fault tolerance and the performance between the various RAID types may differ.
RAID in Cloud Hosting
All of the content that you upload to your new cloud hosting
account will be stored on quick SSD drives which function in RAID-Z. This configuration is built to use the ZFS file system which runs on our cloud hosting platform and it adds another level of protection for your content in addition to the real-time checksum validation that ZFS uses to guarantee the integrity of the data. With RAID-Z, the info is stored on a couple of disks and at least 1 is a parity disk - whenever info is written on it, an extra bit is added, so in the event that any drive stops working for whatever reason, the stability of the info can be verified by recalculating its bits in accordance with what is kept on the production disks and on the parity one. With RAID-Z, the functioning of our system will not be interrupted and it'll continue functioning effectively until the malfunctioning drive is changed and the information is synchronized on it.
RAID in Semi-dedicated Hosting
The information uploaded to any semi-dedicated hosting
account is stored on SSD drives which operate in RAID-Z. One of the drives in such a configuration is used for parity - each time data is copied on it, an extra bit is added. If a disk turns out to be defective, it will be removed from the RAID without interrupting the functioning of the websites since the data will load from the rest of the drives, and when a new drive is added, the info which will be cloned on it will be a blend between the info on the parity disk and data saved on the other hard drives in the RAID. That is done so as to guarantee that the data which is being duplicated is accurate, so once the new drive is rebuilt, it could be incorporated into the RAID as a production one. This is an extra warranty for the integrity of your info because the ZFS file system which runs on our cloud web hosting platform compares a special checksum of all the copies of your files on the different drives to be able to avoid any chance of silent data corruption.
RAID in VPS
The SSD drives which we use on the machines where we generate virtual private servers
work in RAID to make sure that any content you upload will be available and intact at all times. At least a single drive is used for parity - one bit of data is added to any data copied on it. In the event that a main drive stops working, it is changed and the information which will be cloned on it is calculated between the rest of the drives and the parity one. That’s done to ensure that the correct information is copied and that not a single file is corrupted as the new drive will be included in the RAID afterwards. In addition, we use hard disks working in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you will use an even more reliable hosting service as your content will be available on multiple drives irrespective of any type of unexpected hardware malfunction.