3-16
System
Unit
Functions
Hitachi Compute Rack 210H User’s Guide
As the result of standby replacement, the disk A1 and B1 location move to
another disk. In other words, the HDDs constituting a disk array might be
positionally interchanged.
Therefore, in consideration of system management, record the locations of HDDs
each time in case of a failure.
A difference in capacity between the hard disks used in disk arrays A
and B
Depending on the capacity of a reserve disk, a hot spare might not work. The
following hot spare will be applied depending on the capacity of a reserve disk.
This description assumes disk array A < disk array B (A - x < B - x).
If the reserve disk has the same capacity as B-x:
The reserve disk works as a hot spare either in disk array A or B. If the hot
spare is used in disk array A (A and C are applied to the case where
If there
are two or more disk arrays with a RAID level of 1, 5, 6, or 10
), an unused
area will exist on the rebuilt HDD because the reserve disk is greater in
capacity than hard disk A-x used in disk array A.
If the reserve disk has the same capacity as A-x:
The reserve disk works as a hot spare only in disk array A, not in disk array B.
No data can be restored on the disk because the reserve disk is smaller in
capacity than the HDD B-x used in disk array B. Therefore, disk array B
remains in degraded mode.
To prevent the above, fit the capacity of a reserve disk to the disk array or
prepare a reserve disk for each disk array. The priority of a reserve disk used in
case of a failure is as follows:
1 A reserve disk having the same capacity as a failed disk
2 A reserve disk with a small device ID, in order of a storage bay number.
