machine; Lenovo s820 CN
version; 4.4.2 Vibeui
MTK Droid Tool version; 2.5.3
when try to backup the ROM this problem appeared,using the phone storage
the internal storage 2.56GB Available is 0.92GB
the built in storage 1.03GB Available is 0.97GB
then switch to SD card storage 8GB but then again still the same problem
please to refer the picture. if it small please do zoom into it.