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RAID6
RAID 6 extends RAID 5 by adding an additional parity block (Q) created by different calculation method such as
weighting by some factor, and thus uses block-level striping with two parity blocks distributed across all the member
disks. This mode is called "striping with duplex and distributed parity". Accordingly, the total capacity assigned to the
parity is just the same as the capacity of two HDDs. If two of the HDDs configuring a logical drive are defective, data is
still available.
RAID10
Data to be recorded is distributed to two HDDs in mirroring mode. Then, each mirrored data is written onto the HDDs
by striping. This feature achieves the high disk access performance of RAID0 and, in addition, the high reliability of
RAID1.
HDD 1
HDD 2
Stripe 1
Stripe 2
Stripe 4
Parity P (3,4)
Parity P (5,6)
Parity Q (5,6)
Parity Q (7,8)
Stripe 7
HDD 1
HDD 2
Stripe 1
Stripe 1
Stripe 3
Stripe 3
Stripe 5
Stripe 5
RAID1
RAID Controller
HDD 3
Parity P (1,2)
Parity Q (3,4)
Stripe 5
Stripe 8
RAID Controller
HDD 3
Stripe 2
Stripe 4
Stripe 6
RAID1
RAID10
4-39
HDD 4
Parity Q (1,2)
Stripe 3
Stripe 6
Parity P (7,8)
HDD 4
Stripe 2
Stripe 4
Stripe 6
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