RAID is a data storage technology used to increase performance and/or reliability and capacity, but with multiple “levels”, which one is right for you? We go over two of the most common RAID levels here – RAID 0 and RAID 1.
RAID stands for Redundant Array of Independent Disks, and when you create arrays, you can assign what’s known as a RAID level to it. Each RAID level provides the user with a unique combination of storage capacity, redundancy, performance, or all three in some cases. The software that keeps your RAID array ticking along is located in the RAID controller, which can either be located in a separate RAID controller card or can be software-based; although hardware controllers offer better performance. RAID systems can be used with a multitude of interfaces, including SATA, IDE, SCSI or FC. RAID is more than “just a bunch of disks” (JBOD), the term that refers to, well, just a bunch of disks. The RAID level you choose will depend on your needs, and whether you’re a business or just a home user.
RAID 0 is RAID in its purest form. Also known as “striping”, data are split up into blocks, and these get written across all of the drives in the array. It’s easy to implement, and gives the user increased storage capacity; it essentially turns multiple hard drives into a single, higher capacity drive. RAID 0 also offers greater performance, both in terms of read and write speeds, due to both or all of the read/write heads being in operation. There is also no overhead in the form of redundancy, meaning all of the drives’ space is free for the user’s data. However, RAID 0 is not fault-tolerant, meaning that if one drive in the array fails, all of the data in the array is lost. RAID 0 definitely should not be used to store precious data. RAID data recovery from a RAID 0 array is as easy as regular hard drive data recovery, providing only one of the drives in the array is damaged.
RAID 1 results in data being stored at least twice across two or more drives – hence the name “mirroring”. If one drive in the array fails, the RAID controller will continue operating the remaining drive, or drives. Data does not have to be rebuilt – instead, it is simply copied to the replacement drive. RAID 1 arrays provide increased performance, with at least twice the read rate due to all the heads being operated in tandem, and an equal write rate. Like RAID 0, RAID 1 is an incredibly simple technology, making it particularly attractive. What users lose in write speeds they gain in redundancy; this is the ability for the array to carry on operating as normal if one of the drives fails. The downside of RAID 1 arrays is that storage capacity is reduced to that of one drive’s worth due to data having to be mirrored. RAID 1 is a great all-round RAID level for users who want a bit of extra security for their data.
