FUJITSU CentricStor V3.1D - Manual (Page 57)

U41117-J-Z125-7-76 57
CentricStor - Virtual Tape Library Optional system functions
2.9.8.4 Mirrored RAID systems
A mirrored CentricStor system has 1 to a maximum of 4 RAID mirror pairs.
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):
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:
Assignment of the LUNs for DTV
caches (/cache/...)
1st RAID 2nd RAID
(P) x + 0 (S) x + 8
(P) x + 1 (S) x + 9
(P) x + 2 (S) x + 10
(P) x + 3 (S) x + 11
(P) x + 4 (S) x + 12
(P) x + 5 (S) x + 13
(P) x + 6 (S) x + 14
(P) x + 7 (S) x + 15
1stRAID 2ndRAID
ID 1 ID 2
RAID mirror pair 1
3rdRAID 4thRAID
ID 3 ID 4
RAID mirror pair 2
5thRAID 6thRAID
ID 5 ID 6
RAID mirror pair 3
1st RAID
RAID mirror pair
Primary
cache
2nd RAID
Secondary
cache
(P) LUN0
(P) LUN1
(P) LUN2
(P) LUN3
(P) LUN4
(P) LUN5
(P) LUN6
(P) LUN7
(S) LUN8
(S) LUN9
(S) LUN10
(S) LUN11
(S) LUN12
(S) LUN13
(S) LUN14
(S) LUN15
Example of the LUN assignments:
1st RAID 2nd RAID
P = Primary cache
S = Secondary cache