The operating system does not see the expanded RAID array.
The Expand Array Function does not expand the size of the existing RAID volume. It only frees up space on the existing drives by taking the total volume data and spreading it across the additional drive(s). For example, if a RAID 5 array is created across three 15GB hard drives and the maximum size is used for the volume, then the end result would be a 30GB RAID volume. If another 15GB hard drive is added to the Array, the 30GB RAID volume is then spread across all 4 drives and the extra 15GB is available as free space across all 4 drives, which can be used to create another RAID volume.
Local Recovery Console, Advanced RAID Configuration Utility, The original RAID volume is still the same size, No new RAID volume has been created
This applies to: