216 Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1
Figure 6-34   Distributed RAID 6 (for simplification, not all packs are shown)
Figure 6-35 on page 217 shows a single drive failure in this DRAID6 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.