A RAID calculator tool is now available. The useful capacity of a specific configuration is easily visible. RAID Calculator offers you an estimate on the space utilization with various mixed HDD configurations and RAID types. The actual HDD size will be affected by the system partition and can vary between vendors, so the values calculated may differ from the actual results.
Results from the RAID Calculator should be used as a reference only. The decimal prefix is used to show the calculated result of disk-array capacity.
Find here all the answers to the most commonly asked questions about Raid calculator
A controller provides a layer of abstraction between the physical drives and the operating system. Applications and operating systems can define data protection strategies for the logical units a RAID controller provides as groups of disks or sections of drives. Even though they may be made up of pieces of many drives, the logical units appear to programs and operating systems as drives (or portions of drives). The controller can enhance performance and safeguard data in the case of a system crash since it can access numerous copies of data stored on various physical devices.
A RAID 1 mirrored pair typically consists of two disks and creates a perfect replica (or mirror) of a set of data on two or more disks. Given that the data is mirrored across all of the array's disks and that the array can only be as large as its smallest member disk, this design does not support parity, striping, or the spanning of disk space across many disks. When read performance or dependability are more crucial than write performance or the resulting data storage capacity, this arrangement is advantageous.
RAID 1 ensures data redundancy in accordance with the conventional RAID definition. While using a different strategy from RAID 1, other levels also store data redundantly. The safe storage of data is accomplished by RAID 5 and RAID 6. A "non-redundant" array of independent disks is a RAID 0 system, on the other hand, as it operates without redundancy. We compare all available RAID levels and configurations in our RAID level comparison.
Compared to other storage networks, RAID 1 is characterized by its simplicity. All disks contain the same data, i.e., the complete database of the system at all times. With the proper hardware, this means that each hard drive can be operated and used in a separate computer. In addition, the advantage is that the failure of a single component is not a problem: the RAID 1 system can continue to operate without interruption, and the defective hard disk can be replaced at any point in time. RAID 1 has the advantage of providing improved read speeds and additional protection of the hard disks if the controller or the management software enables simultaneous access to more than one storage medium. In the case of the former, this is made possible by parallel access to different sectors, and in the latter case, by comparing the data.
Its greatest strength – complete redundancy – is also its weakness. Since every hard disk in the network must store the same data, lots of potential storage capacity is automatically lost. Conversely, this means that RAID 1 storage is at least twice as expensive (when two hard drives are combined) as individual data carriers with the same storage capacity. Compared to other RAID levels that generate redundancy with the help of parity, the high-cost factor of RAID 1 is a disadvantage.