If you want to expand an array on a HP server platform then you need to do this with the HP ACU (array configuration utility).
Follow the step by step guide below to walk you through how to expand an array.
First we need to launch the HP Array Configuration Utility .( click on the pics for expanded view )
Select “Show Physical View”
Select the array that you would like to expand.
Then select “Expand Array”
You will then get prompted to select which drives you would like to add. Add the drive you require.
Accept the warning and click ok.
The array will now expand, it may take some time depending on the ammount of data to be spread across the drives.