Just in case, here is the correct procedure when resizing RAID array in DSS V6:

1). Apply appropriate Storage extension Key or make sure that your current license key is valid also for the storage size after the LUN size extension,
2). Expand the LUN size using the H/W RAID tools(RAID migration)
3). Perform "Unit rescan" (DSS webgui -> CONFIGURATION ->volume manager -> Vol. groups)
4). PV Resize (DSS Console -> ctrl + alt + X -> 11. PV Resize)
5). Reboot

In case you are using trial version, you don't have to apply the storage extension key because trail version is for unlimited storage.

BR,
Tomek