Dell H800, H700 manual Example of RAID 60 6 + Advantages of RAID

Dell

RAID 0

RAID 6

RAID 6

Parity	Data 1	Data 2	P parity	Q parity	Data 3	Data 4	P parity	Q parity	Parity
			Q parity	Data 6
Generation	Data 5	P parity			Data 7	P parity	Q parity	Data 8	Generation
	P parity	Q parity	Data 9	Data 10	P parity	Q parity	Data 11	Data 12
	Q parity	Data 13	Data 14	P parity	Q parity	Data 15	Data 16	P parity
	Drive 1	Drive 2	Drive 3	Drive 4	Drive 5	Drive 6	Drive 7	Drive 8

Figure 10. Example of RAID 60 (6 + 0)

Advantages of RAID 60

∙Allows creation of largest RAID groups, up to 256 drives (theoretical); large RAID volumes are allowed for up to 192 drives connected to PERC H800

∙High degree of fault tolerance due to 2 parity calculations being done for each RAID 6 subset

∙Medium-to-high write transaction rate

Disadvantages of RAID 60

∙One of the more complex RAID implementations

∙Less space-efficient than RAID 6 since separate parity calculations are done for each RAID 6 subset

∙Retrieval of parity information after a drive failure takes longer than using a mirrored solution

DELL PERC H700 and H800 Technical Guide 28