The data is distributed across a single row. For simplification, not all packs are shown in  Figure 4-47. Figure 4-48 on page 198 shows a single drive failure in the distributed RAID 6 (DRAID 6)  environment. Physical disk 3 failed and the RAID 6 algorithm is using the spare capacity for a  single spare drive in each pack for rebuild (which is marked in green). All disk drives are  involved in the rebuild process, which significantly reduces the rebuild time.  Figure 4-47 Distributed RAID 6 Chapter 4. Storage pools  197