RAID technology takes multiple drives and combines them into a single unit. You might have heard of the term “redundancy”, but what does it actually mean?
Redundant Array of Independent Disks (RAID) provides a number of benefits depending on the configuration, such as increased speed, storage capacity, and redundancy. Redundancy simply means that your systems contains duplicates of files; in the event of failure, you still have data to work with.
Different RAID Levels provide varying degrees of redundancy. RAID 0, or striping, combines a pair of disks, striping data across them You can more storage capacity and higher speeds, but no redundancy. If one drive in a RAID 0 array fails, the data is lost. For this reason, many people don’t consider RAID 0 to be a legitimate form of RAID. RAID 0 is the only RAID level that provides no redundancy.
RAID 1, also known as mirroring, provides data redundancy by mirroring the data on both drives, so if one fails, there is a copy of the data still accessible. RAID 10 combines RAID 0 and RAID 1, and also provides redundancy through the RAID 1 element. RAID 3 uses parity information in order to achieve redundancy, while RAID 5 combines striping and parity for redundancy. Finally. RAID 6 uses striping and double parity to achieve redundnancy.