User has been concerning about how to increase partition size all the time. RAID disk array is employed to improve disk access speed among which raid 5, constituted by several hard disks, is the most popular one. Will the disk data be damaged if users increase RAID 5 size and how could user increase RAID 5 size while insuring the data safety. To answer these questions, user should first come to understand what is raid 5.
RAID, an acronym for Redundant Array of Independent Disks is a technology that provides increased storage reliability through redundancy, combining multiple relatively low-cost, less-reliable disk drives components into a logical unit where all drives in the array are interdependent. This concept was first defined by David A. Patterson, Garth A. Gibson, and Randy Katz at the University of California, Berkeley in 1987 as Redundant Arrays of Inexpensive Disks. Marketers representing industry RAID manufacturers later attempted to reinvent the term to describe a redundant array of independent disks as a means of dissociating a low-cost expectation from RAID technology. RAID 5 distributes parity along with the data and requires all drives but one to be present to operate; drive failure requires replacement, but the array is not destroyed by a single drive failure. Upon drive failure, any subsequent reads can be calculated from the distributed parity such that the drive failure is masked from the end user. The array will have data loss in the event of a second drive failure and is vulnerable until the data that was on the failed drive is rebuilt onto a replacement drive. A single drive failure in the set will result in reduced performance of the entire set until the failed drive has been replaced and rebuilt.
Above is the demonstration is performed on basic disk partition which is still suitable for raid 5 partition. User could obtain the same effect after performing same operation over raid 5 partition without data loss.