proftp不能登录

pulch

启动proftp后,登录时显示:
500 FTP server shut down (Maintanance in progress) -- please try again later

重新启动proftpd:
[root@210 ch]# /etc/rc.d/init.d/proftpd restart
正在关闭 proftpd：                                              [ 完成 ]
正在启动 proftpd：                                              [ 完成 ]
[root@210 ch]#

如此始终不能登录.

proftpd.conf配置如下(应该没有关系):

# This is a basic ProFTPD configuration file (rename it to
# 'proftpd.conf' for actual use.  It establishes a single server
# and a single anonymous login.  It assumes that you have a user/group
# "nobody" and "ftp" for normal operation and anon.
<Global>
IdentLookups                        off
RequireValidShell                off
MaxLoginAttempts                        3
WtmpLog                                NONE
AllowForeignAddress                on
CommandBufferSize                128
DeferWelcome                        on
TimesGMT                                on
</Global>

ServerName                        "roFTPD Server"
ServerType                        standalone
DefaultServer                        on

# Allow FTP resuming.
# Remember to set to off if you have an incoming ftp for upload.
AllowStoreRestart                on

# Port 21 is the standard FTP port.
Port                                21

# Umask 022 is a good standard umask to prevent new dirs and files
# from being group and world writable.
Umask                                022

# To prevent DoS attacks, set the maximum number of child processes
# to 30.  If you need to allow more than 30 concurrent connections
# at once, simply increase this value.  Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd).
MaxInstances                        30

# Set the user and group under which the server will run.
User                                ch
Group                                ch

# To cause every FTP user to be "jailed" (chrooted) into their home
# directory, uncomment this line.
#DefaultRoot ~

# Normally, we want files to be overwriteable.
<Directory />
  AllowOverwrite                on
</Directory>

# Needed for NIS.

PersistentPasswd              off

# Default root can be used to put users in a chroot environment.
# As an example if you have a user foo and you want to put foo in /home/foo
# chroot environment you would do this:
#
# DefaultRoot /home/foo foo
Include                        /etc/proftpd-anonymous.conf