System
Unit
Functions
3-15
Hitachi Compute Rack 210H User’s Guide
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.
1
2
3
4
5
6
A-0
A-1
B-0
B-1
B-2
Reserve
Extension
storage bay
Disk array A
Disk array B
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.
1
2
3
4
5
6
A-0
A-1
B-0
B-1
B-2
Reserve
A-0
Reserve
B-0
B-1
B-2
A-1
Extension
storage bay
Rebuild
Replace disk
(Becomes reserved disk)
Extension
storage bay
Rebuild
Replace disk
(Becomes reserved disk)
1
2
3
4
5
6
A-0
Reserve
B-0
B-1
B-2
A-1
A-0
B-1
B-0
Reserve
B-2
A-1
Extension
storage bay
Rebuild
Replace disk
(Becomes reserved disk)
1
2
3
4
5
6
A-0
B-1
B-0
Reserve
B-2
A-1
A-0
B-1
B-0
A-1
B-2
Reserve
Figure 3-13: Transition of reserve disk
Disk array A: RAID1
Disk array B: RAID5
Reserve disk: Provided
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.
