RAID Protected Data
RAID (“Redundant Array of Inexpensive Disks” or “Redundant Array of Independent Disks”) is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical drives for the purpose of data redundancy, performance enhancement or both. This was in contrast to the earlier concept of highly reliable mainframe disk drives called “big, expensive single disk” (SLED). Data is spread across the drives in one of several ways, called RAID levels, depending on the required level of redundancy and performance. Different schemes, or data striping layouts, are named with the word “RAID” followed by a number, for example, RAID 0 or RAID 1. Each scheme, or RAID level, provides a different balance between key objectives: reliability, availability, performance and capacity. RAID levels greater than RAID 0 provide protection against unrecoverable sector read errors as well as complete physical drive failures.