Redundant Array of Independent Disks, or RAID, is a way of keeping content on several hard drives at the same time. A RAID can be software or hardware based on the HDDs which are used - physical or logical ones, but what is common between them is that they all function as one single unit where data is saved. The biggest advantage of using a RAID is redundancy as the info on all of the drives shall be exactly the same all the time, so even in the event that a drive fails for whatever reason, the info will still be available on the rest of the drives. The overall performance will also improve because the reading and writing processes can be split between various drives, so a single one will not be overloaded. There are different types of RAIDs where the functionality and fault tolerance can vary depending on the exact setup - whether your data is written on all drives in real time or it is written on a single drive and after that mirrored on another, what number of drives are used for the RAID, and many others.
RAID in Cloud Hosting
The SSD drives that our cutting-edge cloud web hosting platform employs for storage work in RAID-Z. This kind of RAID is developed to work with the ZFS file system that runs on the platform and it uses the so-called parity disk - a special drive where data located on the other drives is copied with an extra bit added to it. If one of the disks fails, your sites shall continue working from the other ones and after we replace the malfunctioning one, the information that will be duplicated on it will be recovered from what is stored on the other drives together with the info from the parity disk. This is performed so as to be able to recalculate the bits of every file properly and to validate the integrity of the information duplicated on the new drive. This is another level of security for the content which you upload to your cloud hosting account together with the ZFS file system that compares a special digital fingerprint for each and every file on all of the disk drives in real time.
RAID in Semi-dedicated Servers
The data uploaded to any semi-dedicated server account is saved on SSD drives which function in RAID-Z. One of the drives in type of a setup is used for parity - whenever data is copied on it, an extra bit is added. If a disk turns out to be flawed, it will be taken out of the RAID without interrupting the functioning of the websites as the data will load from the rest of the drives, and when a new drive is added, the info that will be duplicated on it will be a mix between the info on the parity disk and data kept on the other hard drives in the RAID. That is done so as to ensure that the information that is being copied is accurate, so as soon as the new drive is rebuilt, it can be incorporated into the RAID as a production one. This is an extra guarantee for the integrity of your data as the ZFS file system that runs on our cloud Internet hosting platform compares a unique checksum of all copies of your files on the various drives to be able to avoid any chance of silent data corruption.
RAID in VPS Servers
The SSD drives which we use on the physical machines where we set up VPS servers work in RAID to ensure that any content which you upload will be available and intact all of the time. At least one drive is used for parity - one bit of info is added to any data copied on it. In case a main drive breaks down, it is replaced and the info that will be duplicated on it is calculated between the other drives and the parity one. That’s done to ensure that the correct data is copied and that not a single file is corrupted because the new drive will be incorporated into the RAID afterwards. Also, we use hard drives working in RAID on the backup servers, so in case you add this upgrade to your VPS package, you'll use an even more reliable web hosting service since your content will be available on multiple drives irrespective of any sudden hardware failure.