To resize a volume (LUN), modify the settings on ZFSSA.
Caution - Modifying the LUN size (especially reducing its size) has the potential to destroy data on the LUN. Before resizing any LUN that is already in use, ensure that you are aware of the potential risks and can proceed without impacting data.
Navigate from the Shares > Projects screen of the BUI, and select the project that contains the LUN you want to resize (opc).
From the LUNs screen on the Shares tab, click the edit (pencil) button next to the LUN you want to resize.