Dell PowerEdge RAID Controller H710 - Manual (Page 87)

RAID 6 combines dual distributed parity with disk striping. This level of parity allows for two disk failures without
duplicating the contents of entire physical disks.
Figure 8. Example of Distributed Parity (RAID 5)
NOTE: Parity is distributed across multiple physical disks in the disk group.
Figure 9. Example of Dual Distributed Parity (RAID 6)
NOTE: Parity is distributed across all disks in the array.
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