SMB disk size upto 6 times larger than file size

I have Freenas 11.2 U6 running with :-
1] 12GB Ram
2] 4 cores
3] LSI HBA
4] 6 x 2TB red label WDdrives - Raidz2
5] SSDx2 Cache for Slog and Cache

Note : - There is already data hope I don't need to redo it please help.

All is running fine and no hicups. It...

SMB disk size upto 6 times larger than file size