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Configuring Your Server 4-27
RAID5
In RAID5, data is distributed to HDDs by striping 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 written onto 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 with no problems.
RAID Controller
HDD 1
HDD 2
HDD 3
Stripe 2
Parity (3, 4)
Stripe 5
Parity (1, 2)
Stripe 3
Stripe 6
Stripe 1
Stripe 4
Parity (5, 6)
RAID6
A RAID 6 extends RAID 5 by adding an additional parity block (Q) created by different calculation
method such as weighting by some factor, thus it uses block-level striping with two parity blocks
distributed across all 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 any two of the HDDs configuring a logical drive are defected, data is still available with
no problems.
RAID Controller
HDD 1
HDD 2
Stripe 1
HDD 3
Stripe 4
Stripe 2
Parity P (3,4)
Parity P (1,2)
Parity Q (3,4)
Parity P (5,6)
Parity Q (5,6)
Stripe 5
HDD 4
Parity Q (1,2)
Stripe 3
Stripe 6
Parity Q (7,8)
Stripe 7
Stripe 8
Parity P (7,8)
Summary of Contents for Express5800/120Rj-2
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Page 19: ...Notes on Using Your Server 1 3 Internal View ...
Page 34: ...1 18 Notes on Using Your Server This page is intentionally left blank ...
Page 90: ...3 24 Setting Up Your Server This page is intentionally left blank ...
Page 164: ...4 74 Configuring Your Server 3 Setting menu for VD 0 is displayed ...
Page 172: ...4 82 Configuring Your Server This page is intentionally left blank ...
Page 240: ...7 12 Maintenance This page is intentionally left blank ...
Page 354: ...9 78 Upgrading Your Server This page is intentionally left blank ...
Page 364: ...C 2 IRQ This page is intentionally left blank ...
Page 412: ...E 24 Installing Windows Server 2003 This page is intentionally left blank ...
Page 414: ...F 2 Using a Client Computer Which Has a CD Drive This page is intentionally left blank ...
Page 418: ...G 4 Product Configuration Record Table This page is intentionally left blank ...