sheshman

with your help,i've found the problem. As you can see on screenshot it was returning I/O error for one of the folders on USB Drive, so it wasn't an important one i deleted with rmdir command, now it works perfectly. Thanks for your time and support.

oh sorry about that, i'm rookie on unix based systems. Here are the output of ls -la under /e-data when i run ls it shows "90aa2d877a5254732fba90420060a799" i believe it's my usb hdd because when i "cd 90aa2d877a5254732fba90420060a799" and "ls" i can show my folders in usb drive

This is the output of pwd-> ls -la

Thanks Dexter,i already checked those subjects but no luck so far

good point :) i don't think it's power issue because when i go \\mynasip i can see external usb drive and files in it