ok, so you have pretty much all of array's capacity mapped , that's why symdev list output  and symdev list -firstport are close.  You can use symmaskdb -sid 1234 list no_assignment ..to see if you have devices that are mapped to FAs but are not masked. Could be potential candidates to be reclaimed.
Hi,  I tried the command symdev -sid xxx list but the output gives the total configured space for the array, is there any command to check the total ALLOCATED capacity for the entire array.  Thank you
CMD for total allocated storage for DMX array