Raid5; Raid10 - NEC Promise SuperTrak EX8350 User Manual

2-4. RAID5

In RAID5, data is distributed to HDDs by striping as well as in RAID0 and, at the same time, the parity
(redundant data) is distributed to the HDDs. This mode is called "striping with distributed parity".
Each of stripe x, stripe x+1, and parity (x, x+1) created from stripe x and stripe x+1 is recorded to a specific
HDD. Accordingly, the total capacity assigned to the parity is just the same as the capacity of a single HDD. If
any one of the HDDs configuring a logical drive is defected, data is still available without problems.

2-5. RAID10

Data is distributed to HDDs by striping and the stripes are recorded by mirroring. Therefore, RAID10 can
realize the disk access performance as high as RAID0 and the reliability as high as RAID1 at a time.
Disk array controller
Disk 1
Stripe 1
Stripe 2
Disk array controller
Disk 1
Stripe 1
Stripe 4
Parity (5, 6)
Disk array controller
Disk 1 Disk 2
Stripe 1 Stripe 2
Stripe 3 Stripe 4
Stripe 5 Stripe 6
RAID0
Disk 2
Stripe 1
Stripe 2
Disk 2 Disk 3
Stripe 2
Parity (1, 2)
Parity (3, 4)
Stripe 3
Stripe 5
Stripe 6
Disk 3
Stripe 1
Stripe 3
Stripe 5
RAID0
RAID1
Disk 4
Stripe 2
Stripe 4
Stripe 6
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