Hitachi Compute Rack CR 210H User Manual page 37

Reserve disk
Install a reserve disk same as disk type, capacity and rotation speed. If set for
"global hot spare", install largest-capacity HDD.
Note that if there are two or more disk arrays, an attempt to set a reserve disk as
a "global hot spare" will cause the following event. Be extremely careful with the
operation.
A reserve disk example is described below by using the following disk array.
Extension
storage bay
Figure 3-12: Example for install reserve disk
Two or more disk arrays with a RAID level of 1, 5, 6, or 10
The reserve disk functions as a hot spare on either disk array. Depending on a
HDD hot spare, the following configuration is applied.
A
A failure occurs
on HDD A-1 of
disk array A.
B
A failure occurs
on HDD B-1 of
disk array B.
C
A failure occurs
on HDD A-1 of
disk array A.
Figure 3-13: Transition of reserve disk
1
A-0
Disk array A
2
A-1
3
B-0
4 B-1 Disk array B
5
B-2
6
Reserve
1
Extension
storage bay
2
3
4
5
6
Reserve
1
Extension
storage bay
2
Reserve
3
4
5
6
1
Extension
storage bay
2
3
4
Reserve
5
6
System Unit Functions
Hitachi Compute Rack 210H User's Guide
Disk array A: RAID1
Disk array B: RAID5
Reserve disk: Provided
A-0
A-1
B-0
B-1
Rebuild
B-2
A-0
B-0
Rebuild
B-1
B-2
A-1
A-0
B-1
B-0
B-2
Rebuild
A-1
A-0
Reserve Replace disk
(Becomes reserved disk)
B-0
B-1
B-2
A-1
A-0
B-1
B-0
Replace disk
Reserve
(Becomes reserved disk)
B-2
A-1
A-0
B-1
B-0
A-1
B-2
Replace disk
Reserve
(Becomes reserved disk)
3-15