create directory failed in vsftpd
i have a problem that my vsftpd cannot create directory, i don't know why. I can put and erase file but cannot put or create directory.
227 Entering Passive Mode (127,0,0,1,125,68)
150 Here comes the directory listing.
-rwxr-xr-x 1 500 500 324511 Jun 10 03:43 countdown.psd
226 Directory send OK.
ftp> mkdir tes
550 Create directory operation failed.
does anyone have suggestion to fix it.