Replacing a Low Capacity Drive with a Large Capacity Drive on an Existing Array on an AMI RAID Controllers - HP Servers

Free disk space on a larger capacity replaced drive may not be configured until the other drives in the same array are replaced with the same capacity. Related document "Using 18GB Hard Disk Drive to Replace 4GB and 9GB Hard Disk Drives"

	Configure the free disk space on a larger capacity drive in an array

If a failed hard disk drive is replaced with a larger capacity hard disk drive, the free space on the larger capacity drive cannot be configured until the other drives in the same array are replaced with the equal or larger capacity.

Here is an example of a RAID array with one failed drive.

· A0-0 9 GB Online
· A0-1 9 GB Online
· A0-2 9 GB Failed

The failed 9 GB drive is replaced by an 18 GB drive. After the drive rebuild, the array configuration becomes:

· A0-0 9 GB Online
· A0-1 9 GB Online
· A0-2 18 GB Online

However, the 9 GB of free space on A0-2 is not useable because the other two drives in the array have only 9 GB capacities.

Fail the 9 GB drive on A0-1 and replace it with an 18 GB drive. The RAID array becomes:

· A0-0 9 GB Online
· A0-1 18 GB Online
· A0-2 18 GB Online

In addition to the 9 GB unusable free spaces on A0-2, A0-1 has an unusable free space of 9 GB.

In order for the unusable free spaces to be included in the RAID array without reconfiguring the entire array, the 9 GB drive on A0-0 must be replaced with an 18 GB drive. The RAID array with all 18 GB drives looks like this:

· A0-0 18 GB Online
· A0-1 18 GB Online
· A0-2 18 GB Online

Now all the drives in the original configuration have been replaced with drives that have larger capacities.

NOTE:

HP recommends back up all data before replacing drives in an array.

Following the steps configure the free space in the array, resulting in disabling the capacity expansion feature on the HP NetRAID controller.

1.       Boot into the HP NetRAID Express Tools by pressing Ctrl + M.

2.       Go to Configure, then View/Add/Delete.

3.       Highlight the first drive, in the above example, A0-0, which needs to be configured.

4.       Press the F10 key to bring up the Logical Drives Configured screen, which includes a menu for configuring the free space into a new logical drive.

This process has been tested on RAID levels 1, 3, 5, 10 and 50. It is possible to configure half of the array with RAID 50 or RAID 10. Make the new array any of the aforementioned RAID levels assuming the correct amount of disks is available, for the appropriate RAID level.

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