Figure 7 Hot Spare Selection Criteria - Search Order For Drive Enclosures (Eternus Dx900 S5, Example 1); Table 25 Hot Spare Selection Criteria - Drives (Eternus Dx900 S5) - Fujitsu ETERNUS DX S5 Series Design Manual

2. Basic Functions
RAID Functions
Hot spare selection criteria (drives)
•
Drives that meet the following criteria are searched.
Table 25
Priority order
1
2
3
4
*1: If multiple drives are applicable, priority is given to the drives in ascending order of the enclosure number and the drive slot
number.
*2: When there are multiple hot spares with a larger capacity than the failed drive, the hot spare with the smallest capacity among
them is used first.
The following figures show examples of the search order for drive enclosures if a drive fails in the ETERNUS
DX900 S5 when the RAID group is configured across controller enclosures.
Figure 7
1)
CE#0
DE#04
DE#08
DE#0C
CE#1
DE#14
DE#18
DE#1C
Search order (order of priority described in
1:
2:
3:
4:
Hot Spare Selection Criteria – Drives (ETERNUS DX900 S5)
Selection criteria
A hot spare with the same type, same capacity, and same rotational speed (for disks) as the failed drive (*1)
A hot spare with the same type and same rotational speed (for disks) as the failed drive but with a larger
capacity (*1) (*2)
A hot spare with the same type and same capacity as the failed drive but with a different rotational speed (for
disks) (*1)
A hot spare with the same type as the failed drive but with a larger capacity and a different rotational speed
(for disks) (*1) (*2)
Hot Spare Selection Criteria – Search Order for Drive Enclosures (ETERNUS DX900 S5, Example
RAID group
13
DE#01
1
DE#05
Failure
25
DE#09
37
DE#0D
96
DE#11
49
DE#15
61
DE#19
73
DE#1D
(Priority order 1)
(Priority order 3)
(Priority order 4)
(Priority order 5)
14
DE#02
2
DE#06
26
DE#0A
38
DE#0E
85
DE#12
50
DE#16
62
DE#1A
74
DE#1E
Table 24)
46
15 24
DE#E3
3 12
DE#E7
27 36
DE#EB
39 48
DE#EF
86 95
DE#F3
51 60
DE#F7
63 72
DE#FB
75 84
DE#FF
Design Guide