RAID, or redundant array of independent disks, transforms multiple hard drives into a single logical unit – but which RAID setup, or level, should home users choose?
When deciding on what RAID level to choose, it is first necessary to ascertain what benefits you are looking for over a standard hard drive or solid-state drive (SSD). RAID combines multiple hard drives for the purposes of storage capacity, performance, and data redundancy. Some RAID levels let you take advantage of the storage capacity of the drives, while some duplicate data for ease of rebuilding. Almost all RAID levels offer at least some improvement in either read or write speeds, often both. The term “redundancy” simply means that there are more than one copy of your data, so that in the event of one or more (depending on the RAID level) drives failing, you will be able to rebuild.
RAID at its most basic is RAID 0, which is also known as striping, as data is striped across both disks in the array, creating a single logical unit. With a RAID 1 array, you get enhanced performance, due to the read/write heads working in tandem – this is true of both read and write speeds. You also get to take advantage of the total storage capacity of the two drives; for example, two 1TB drives in a RAID 0 array gives you a total of two terabytes of usable storage. However, in a trade-off for storage capacity, RAID 0 offers no redundancy. Files may be stored anywhere across both disks, so if one drive fails, a professional data recovery specialist will need to take a look at it.
Another common RAID level is RAID 1, which is also called mirroring, As the name suggests, data in a RAID 1 array is mirrored across both drives. This gives you one drive’s worth of redundancy, so you will be able to carry on accessing your files if a single drive fails. Additionally, you get faster read speeds as the heads in both drives are working at the same time, but no improvement on write speeds, as data has to be written twice. With RAID 1, you are also sacrificing the equivalent of one drive’s worth of storage capacity due to the data being mirrored.
It really depends what you as a home user are looking for from RAID. RAID 0 offers increased performance and speeds, while lacking redundancy, while RAID 1 offers improved read speeds and redundancy, but lacks faster write speeds and storage capacity. One way around this is to try RAID 10. Sometimes known as RAID 1+0, as you might have guessed, RAID 10 combines the mirroring element of RAID 1 with the striping element of RAID 0. You will need at least four drives for RAID 10, and data is striped across mirrored pairs, giving the user a full intact copy of all data; when one drive in a pair fails, the array can rely on the other one. However, due to lacking parity data, RAID 10 cannot withstand more than one failed drive.
