Appendix B: Using the ARC Utility 54
To modify the Write Cache setting for an array, press Ctrl+W.
The ACU allows you to use drives of different sizes in a RAID 1. However, during a
build operation, only the smaller drive can be selected as the source drive.
When migrating from single volume to RAID 0, migrating from a larger drive to a
smaller drive is allowed. However, the destination drive must be at least half the
capacity of the source drive.
It is not recommend that you migrate or build an array on Windows dynamic disks
(volumes), as it will result in data loss.
5When you are finished, press Done.
Managing Arrays
Select the Manage Arrays option to perform these tasks:
Rebuild Arrays
View Array Properties
Delete Arrays
Enable/Disable Write Cache
Verify Arrays
The following sections describe these operations in greater detail.
Rebuilding Arrays
Note: Rebuilding applies to Fault Tolerant arrays (RAID 1) only.
Before rebuilding an array, note the following:
If no spare exists and a hard disk drive fails, you need to create a spare before you can
rebuild an array. See Adding/Deleting Hotspares on page 56 before continuing your
rebuild.
If there is any medium error occuring on the disk while rebuilding, the operation is
stopped and the array state is marked as degraded. You will be informed about the
error (LBA no and port number of the drive are displayed).
By replacing a failed drive of a RAID 1 array with a new drive, you can rebuild to get the array
to Optimal status and assume fault tolerance. You can perform a rebuild in the following ways:
System Shutdown Re build
You can shut down the system and replace the failed drive with a new one (of equal or
greater capacity). When the system is booted, you can assign the new drive as a spare, and
this will start the Rebuild task. All the data from the good drive is copied to the new one,
and the original RAID 1 array is recreated.
Manual Rebuild
aFrom the Main Menu, select Man age Arrays. From the List of Arrays, select the array
you want to rebuild.
bPress Ctrl+R to rebuild.