RAID, or Redundant Array of Independent Disks, is a technology for saving data on several hard disk drives that operate together as one single logical unit. The drives can be physical or logical i.e. in the latter case one drive is split into separate ones using virtualization software. Either way, the very same data is saved on all the drives and the main advantage of employing such a setup is that in the event that a drive breaks down, the data will remain available on the other ones. Employing a RAID also boosts the overall performance as the input and output operations will be spread among a couple of drives. There are several kinds of RAID dependant upon how many hard disks are used, whether writing is done on all drives in real time or just on one, and how the info is synced between the drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. These factors show that the error tolerance as well as the performance between the different RAID types could differ.
RAID in Cloud Website Hosting
All the content which you upload to your new cloud website hosting account will be held on fast SSD drives which operate in RAID-Z. This configuration is built to work with the ZFS file system which runs on our cloud web hosting platform and it adds an additional level of security for your content in addition to the real-time checksum verification that ZFS uses to guarantee the integrity of the data. With RAID-Z, the info is saved on a couple of disks and at least 1 is a parity disk - whenever info is recorded on it, an additional bit is added, so in the event that any drive stops functioning for whatever reason, the stability of the info can be verified by recalculating its bits based on what is stored on the production drives and on the parity one. With RAID-Z, the operation of our system won't be interrupted and it will continue operating efficiently until the malfunctioning drive is changed and the data is synchronized on it.
RAID in Semi-dedicated Servers
The information uploaded to any semi-dedicated server account is kept on SSD drives which operate in RAID-Z. One of the drives in such a setup is used for parity - each time data is copied on it, an extra bit is added. In case a disk turns out to be flawed, it will be removed from the RAID without disturbing the operation of the websites as the data will load from the rest of the drives, and when a brand new drive is included, the data that will be copied on it will be a combination between the information on the parity disk and data saved on the other drives in the RAID. That is done in order to ensure that the information which is being copied is correct, so as soon as the new drive is rebuilt, it can be included in the RAID as a production one. This is an additional warranty for the integrity of your info because the ZFS file system which runs on our cloud hosting platform analyzes a unique checksum of all the copies of your files on the separate drives so as to avoid any possibility of silent data corruption.
RAID in VPS Servers
The SSD drives which we use on the physical machines where we generate VPS servers operate in RAID to ensure that any content that you upload will be available and intact at all times. At least 1 drive is used for parity - one bit of info is added to any data cloned on it. If a main drive fails, it is replaced and the data that will be duplicated on it is calculated between the rest of the drives and the parity one. This is done to make sure that the correct information is copied and that no file is corrupted since the new drive will be incorporated into the RAID afterwards. Also, we use hard disk drives operating in RAID on the backup servers, so in the event that you add this upgrade to your VPS plan, you will use an even more reliable web hosting service because your content will be available on multiple drives irrespective of any sort of unexpected hardware malfunction.