Thank you Flarup so much to solve my big problem I accidently upgrade FW 5.2-5644 to Ver; 6.0-7321 and XPEnology boot usb is not support 6.0 NAS disk can not access, I use DSM 5.2-5644 install again and select clear install, all data will keep, you just lost all your setting, but it's ok to set setting again in 1 hour, so thanks again!