Method for reorganizing the data on a RAID-4 or RAID-5 array in the absence of one disk

摘要

In a storage system having a plurality of disks arranged in a RAID array with one of the disks failed, a method of reorganizing the data on the RAID array at the time of failure to prevent both a decrease in performance of the array and reliability of the data and an increase in the cost of operation. Data from the failed disk is regenerated one strip at a time and written onto the original parity chunk for the strip. The resulting fully folded array has the characteristics of a RAID level 0 array. When a replacement disk is inserted into the array the process is reversed to bring the fully folded array back to a fully redundant condition.