默认的vsftpd日志很简单。出现问题时，不容易找到原因。
以下参数，打开详细日志。

Activate logging of uploads/downloads.
xferlog_enable=YES
#
You may override where the log file goes if you like. The default is shown
below.
xferlog_file=/users/vsftp_nobody/vsftpd.log
#
If you want, you can have your log file in standard ftpd xferlog format
xferlog_std_format=NO
#The log_ftp_protocol=YES will log every FTP protocol transaction between the client and the server (this is the most detailed log you can get).
log_ftp_protocol=YES

注意，在log_ftp_protocol=YES时，这一项必须是no：xferlog_std_format=NO。否则会得到：

500 OOPS: bad bool value in config file for: log_ftp_protocol

附件：vsftpd.conf参数详解