What is RAID? Just how does RAID work? Find out about the benefits of using a RAID-equipped server.
RAID, or Redundant Array of Independent Disks, is a technology of saving data on multiple hard disks which operate together as a single logical unit. The drives can be physical or logical i.e. in the aforementioned case one drive is split into independent ones using virtualization software. In either case, exactly the same info is kept on all the drives and the key advantage of using this type of a setup is that if a drive stops working, the data will remain available on the remaining ones. Using a RAID also enhances the performance as the input and output operations will be spread among a number of drives. There are several kinds of RAID depending on how many hard drives are used, whether writing is carried out on all drives in real time or just on a single one, and how the info is synchronized between the hard drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. These factors mean that the error tolerance and the performance between the different RAID types can vary.
RAID in Shared Hosting
All of the content that you upload to your new shared hosting
account will be stored on fast SSD drives that work in RAID-Z. This setup is built to employ the ZFS file system that runs on our cloud Internet hosting platform and it adds one more level of security for your content in addition to the real-time checksum verification that ZFS uses to ensure the integrity of the data. With RAID-Z, the data is saved on a couple of disks and at least one is a parity disk - whenever info is recorded on it, an extra bit is added, so in the event that any drive fails for some reason, the integrity of the information can be verified by recalculating its bits based on what is kept on the production hard disks and on the parity one. With RAID-Z, the functioning of our system will not be interrupted and it will continue functioning efficiently until the malfunctioning drive is replaced and the information is synchronized on it.
RAID in Semi-dedicated Hosting
The data uploaded to any semi-dedicated hosting
account is kept on SSD drives that work in RAID-Z. One of the drives in type of a configuration is used for parity - any time data is cloned on it, an additional bit is added. In case a disk turns out to be problematic, it will be taken out of the RAID without disturbing the work of the sites because the data will load from the remaining drives, and when a new drive is added, the info that will be copied on it will be a combination between the info on the parity disk and data stored on the other hard disks in the RAID. This is done so as to guarantee that the information that is being duplicated is accurate, so once the new drive is rebuilt, it could be included in the RAID as a production one. This is an additional guarantee for the integrity of your data because the ZFS file system that runs on our cloud hosting platform analyzes a special checksum of all of the copies of the files on the various drives to be able to avoid any probability of silent data corruption.
RAID in VPS Web Hosting
The SSD drives which we use on the machines where we generate virtual private servers
function in RAID to ensure that any content that you upload will be available and intact at all times. At least one drive is used for parity - one bit of information is added to any data cloned on it. In the event that a main drive stops working, it is replaced and the info that will be duplicated on it is calculated between the rest of the drives and the parity one. That’s done to make sure that the correct info is copied and that no file is corrupted as the new drive will be included in the RAID afterwards. Also, we use hard drives operating in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you'll use an even more reliable Internet hosting service because your content will be available on multiple drives regardless of any unforeseen hardware malfunction.