It seems that 5.3.3 firmware does not recognise user quota settings from NAS.
I have DS-2CD3232-I5 and 2332 turret camera, both on 5.1 version, which recognised quota settings on NAS as HDD (CIFS per user user quota), but 2135F-IS on 5.3.3. does not recognised quota, and sees full HDD size...