RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which allows a system to employ many hard drives as a single logical unit. Simply put, all drives are used as one and the info on all of them is the same. This type of a setup has two key advantages over using just a single drive to keep data - the first is redundancy, so in case one drive fails, the info will be accessed from the remaining ones, and the second is improved performance because the input/output, or reading/writing operations will be spread among different drives. You can find different RAID types depending on how many drives are employed, whether reading and writing are both done from all the drives concurrently, if data is written in blocks on one drive after another or is mirrored between drives in the same time, etc. According to the particular setup, the error tolerance and the performance may vary.
RAID in Cloud Website Hosting
The SSD drives that our cutting-edge cloud web hosting platform employs for storage work in RAID-Z. This sort of RAID is intended to work with the ZFS file system which runs on the platform and it employs the so-called parity disk - a specific drive where information stored on the other drives is cloned with an extra bit added to it. In the event that one of the disks stops working, your Internet sites will continue working from the other ones and after we replace the malfunctioning one, the information that will be copied on it will be recovered from what is stored on the other drives as well as the data from the parity disk. This is performed in order to be able to recalculate the bits of each and every file properly and to validate the integrity of the info copied on the new drive. This is one more level of security for the content which you upload to your cloud website hosting account together with the ZFS file system that analyzes a unique digital fingerprint for each file on all the hard drives in real time.
RAID in Semi-dedicated Hosting
The data uploaded to any semi-dedicated hosting account is saved on SSD drives that function in RAID-Z. One of the drives in this kind of a configuration is used for parity - every time data is cloned on it, an extra bit is added. If a disk turns out to be faulty, it will be removed from the RAID without disturbing the operation of the sites as the data will load from the other drives, and when a brand new drive is added, the data which will be copied on it will be a combination between the data on the parity disk and data saved on the other hard drives in the RAID. That is done to ensure that the data that is being duplicated is accurate, so the moment the new drive is rebuilt, it could be integrated into the RAID as a production one. This is one more guarantee for the integrity of your information as the ZFS file system that runs on our cloud Internet hosting platform compares a unique checksum of all copies of the files on the different drives to avoid any probability of silent data corruption.
The physical servers where we generate virtual private server use extremely fast SSD drives that will raise the speed of your websites noticeably. The disk drives function in RAID to ensure that you won't lose any data as a result of a power loss or a hardware failure. The production servers use a variety of drives where the info is saved and one disk is used for parity i.e. one bit is added to all of the info copied on it, that makes it much easier to recover the site content without loss if a main drive fails. In case you choose our backup service, the data will be kept on a separate machine which uses standard hard-disk drives and despite the fact that there's no parity one in this case, they are also in a RAID to ensure that we will have a backup copy of your website content all of the time. With this particular configuration your information will always be safe as it will be available on multiple drives.