Here are the steps to expand a RAID 5 when using the Intel(R) RAID web console 2:
- Right click on the drive group and select modify group, confirm and next.
- The drives that are available for expansion will show as grayed out until you select the RAID level (RAID 5 in your case)
- Select the RAID level and then the drive as "unconfigured good" will appear listed, select it.
- Press next, a little summary of the configuration will show and then click finish to end the expansion procedure.
Notice that performance will degrade depending of the size of the RAID array configuration. Drive group should remain the same.