Patent ID: 8176247
Filing Date: 2012-05-08
Classification: G06F

Abstract:
1. A method of protecting a RAID system from multiple failures, the method comprising: providing a system comprising a plurality of data banks coupled to each of the other data banks and each of one or more hosts via a network, each data bank executing a distributed RAID application; establishing a volume on the plurality of data banks, where the volume comprises a set of segments and the set of segments are stored on the plurality of data banks, wherein executing a first command in conjunction with the volume comprises determining at least a first data bank by accessing a global table comprising a permutation of the data banks and a first RAID level associated with the volume; implementing the first RAID level in conjunction with the volume, wherein implementing the first RAID level comprises storing a set of network parity (NP) segments, each NP segment corresponding to one or more of the set segments such that each NP segment does not reside on the same data bank as the corresponding one or more of the set of segments; implementing a second RAID level within the plurality of data banks, wherein implementing the second RAID level for a first data bank comprises, for the set of segments stored on the first data bank: storing a set of parity of data (POD) segments, each POD segment corresponding to one or more of the set of data segments on the first data bank such that each POD segment does not reside on the same disk as the corresponding one or more of the set of segments on the first data bank; and storing a set of parity of parity (POP) segments, each POP segment corresponding to one or more of the set of NP segments stored on the first data bank such that each POP segment does not reside on the same disk as the corresponding one or more of the set of NP segments on the first data bank.