RAID 50 ArraysA RAID 50 array is built from six to forty-eight disk drives configured as two or more RAID 5 arrays, andstripes stored data and parity data across all disk drives in both RAID 5 arrays. (For more information,see RAID 5 Arrays on page 77.)The parity data provides data protection, and striping improves performance. RAID 50 arrays also providehigh data transfer speeds.Drive segment size is limited to the size of the smallest disk drive in the array. For example, three 250GB disk drives and three 400 GB disk drives comprise two equal-sized RAID 5 arrays with 500 GB ofstored data and 250 GB of parity data. The RAID 50 array can therefore contain 1000 GB (2 x 500 GB)of stored data and 500 GB of parity data.In this figure, P represents the distributed parity data.RAID 5BRAID 50Logical Drive=1000 GBplus ParityRAID 5AEach RAID 5 Logical Drive has500 GB Data Storage250 GB Parity DataDrive 1250 GBDrive 2250 GBDrive 3250 GB Drive 4400 GBDrive 5400 GBDrive 6400 GBTotal UnusedSpace = 150 GB2, 6, P 4, P, 10 P, 8, 121, 5, P 3, P, 9 P, 7, 1179Proprietary and Confidential to PMC-Sierra, Inc.Document No.: CDP-00277-02-A Rev. A, Issue:Serial Attached SCSI RAID Controllers Installation and User's Guide
