资 源 简 介
A Redundant Array of Independent Disks (RAID) array is a hard-disk drive (HDD) array where
part of the physical storage capacity stores redundant information. Data is regenerated from
the physical storage if one or more of the disks in the array (including a single failed disk sector)
or the access path to it fails.
There are many different levels of RAID. The RAID level used depends on several factors:
• Overhead of reading and writing data
• Overhead of storing and maintaining parity
• Mean Time to Data Loss (MTDL)
The newest level of RAID is RAID6, which has two implementations (Reed-Solomon P+Q or
Double Parity). RAID6 is the first RAID level that allows the simultaneous loss of two disks,
resulting in an improved MTDL over RAID5.
