6500 Disk Array User’s Guide 21020690 B
Chapter 4 Maintenance, Troubleshooting & Hardware Replacement
Types of Rebuilds Page 4 - 25
Types of Rebuilds
The next task required is to rebuild data onto the new drive in the array.
In this nine-disk array, eight drives are used for data storage and the ninth for
parity checking. No matter which drive is replaced, it is possible to use the
remaining drives to reconstruct the missing information.
Off-Line
Rebuild
An off-line rebuild occurs when the subsystem is off-line a nd remains of f-line
throughout the rebuild process. During an off-line rebuild the array will be
unavailable for use. To complete the rebuild in the shortest amount of time, do
an off-line rebuild, with the percentage of time dedicated to rebuilding set to
99%.
Percentage
Rebuild
A percentage rebuild occurs when the subsystem is on-line. During a
percentage rebuild the drive's data is rebuilt concurrent with other operations.
The percentage of time allotted to the rebuild process can be selected via the
display/operation panel. Completion time for a percentage rebuild will vary
with the percentage selected and the intensity of system activity directed at the
array and the size of the disk.
During
Rebuild
Following is a brief description of what happens as the array rebuilds a drive.
The controller board will:
1. Apply power to the replacement drive's drive spindle motor, spinning
up the drive.
2. Rebuild the data. In this step, data is read from other drives and
reconstructed on the new drive.
Note If the rebuild is interrupted, for example, if the array is powered
down or the rebuild is canceled, the process will terminate in an
orderly manner. However, when the rebuild is re-initiated, it will
not resume where it stopped but will start over, repeating both of
the above steps.
Completing
the Rebuild
Upon completion of the rebuild process, the display/operation panel will revert
from indicating the type of rebuild in process and will display
. Subsystem operation will continue normally.