Mirrored Raid Systems - Fujitsu Siemens Computers pmn User Manual

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2.9.8.4

Mirrored RAID systems

A mirrored CentricStor system has 1 to a maximum of 4 RAID mirror pairs.
RAID mirror pair 1
1stRAID 2ndRAID
ID 1
Figure 23: Example of a CentricStor mirror system with 3 RAID mirror pairs
In a RAID mirror pair, one RAID system contains only primary caches, the other only
secondary caches (mirror caches):
1st RAID
Primary
cache
Figure 24: Primary and secondary caches in a RAID mirror pair
Such a mirror pair is defined by the corresponding assignment of the LUNs, as shown in the
example (where x is in the range 0 through 7) below:
U41117-J-Z125-7-76
RAID mirror pair 2
3rdRAID 4thRAID
ID 2 ID 3
RAID mirror pair
2nd RAID
Secondary
cache
Assignment of the LUNs for DTV
caches (/cache/...)
1st RAID
(P) x + 0
(P) x + 1
(P) x + 2
(P) x + 3
(P) x + 4
(P) x + 5
(P) x + 6
(P) x + 7
RAID mirror pair 3
5thRAID 6thRAID
ID 4 ID 5
Example of the LUN assignments:
1st RAID
(P) LUN0
(P) LUN1
(P) LUN2
(P) LUN3
(P) LUN4
(P) LUN5
(P) LUN6
(P) LUN7
2nd RAID
(S) x + 8
(S) x + 9
(S) x + 10
(S) x + 11
(S) x + 12
(S) x + 13
(S) x + 14
(S) x + 15
Optional system functions
ID 6
2nd RAID
(S) LUN8
(S) LUN9
(S) LUN10
(S) LUN11
(S) LUN12
(S) LUN13
(S) LUN14
P = Primary cache
(S) LUN15
S = Secondary cache
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