What is RAID? How exactly does RAID work? Find out about the advantages of using a RAID-equipped server.
RAID, or Redundant Array of Independent Disks, is a technology for keeping data on a number hard drives which work together as one logical unit. The drives could be physical or logical i.e. in the latter case one drive is divided into independent ones using virtualization software. In any case, the same info is kept on all the drives and the main benefit of employing such a setup is that in case a drive breaks down, the data will still be available on the other ones. Using a RAID also improves the performance since the input and output operations will be spread among a couple of drives. There are several types of RAID depending on how many hard drives are used, whether writing is carried out on all the drives in real time or just on one, and how the info is synchronized between the hard drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors suggest that the error tolerance as well as the performance between the different RAID types may vary.
RAID in Shared Web Hosting
The SSD drives which our cutting-edge cloud web hosting platform employs for storage work in RAID-Z. This type of RAID is designed to work with the ZFS file system which runs on the platform and it employs the so-called parity disk - a specific drive where info kept on the other drives is duplicated with an extra bit added to it. If one of the disks fails, your websites shall continue working from the other ones and after we replace the malfunctioning one, the information which will be duplicated on it will be rebuilt from what is stored on the other drives together with the information from the parity disk. This is done so as to be able to recalculate the elements of each file properly and to validate the integrity of the data cloned on the new drive. This is one more level of security for the info that you upload to your shared web hosting
account together with the ZFS file system which analyzes a special digital fingerprint for each and every file on all disk drives in real time.
RAID in Semi-dedicated Servers
The RAID type that we employ for the cloud web hosting platform where your semi-dedicated server
account will be created is known as RAID-Z. What is different about it is that at least 1 of the disks is used as a parity drive. Put simply, whenever any data is duplicated on this special disk drive, one more bit is included to it and in case a problematic disk is replaced, the information that will be copied on it is a combination of the data on the other disk drives in the RAID and that on the parity one. It's done this way to make sure that the data is intact. Throughout this process, your websites will be functioning normally as RAID-Z allows for an entire drive to fail without service disturbances and it simply works by using one of the remaining ones as the main production drive. Employing RAID-Z together with the ZFS file system that uses checksums to warrant that no data will get silently corrupted on our servers, you won't ever need to worry about the integrity of your files.
RAID in VPS Servers
If you take advantage of one of our VPS server
packages, any content you upload will be kept on SSD drives that function in RAID. At least 1 drive is used for parity to ensure the integrity of the information. In simple terms, this is a special drive where information is copied with one bit added to it. If a disk in the RAID fails, your websites will continue working and when a new disk takes the place of the defective one, the bits of the information that will be copied on it are calculated using the healthy and the parity drives. By doing this, any chance of corrupting data during the process is prevented. We also employ conventional hard disk drives which work in RAID for storing backups, so if you add this service to your VPS plan, your site content will be saved on multiple drives and you won't ever need to worry about its integrity even in the event of multiple drive failures.