ubuntu16 允许root用户登录

ubuntu16上 PermitRootLogin yes 

 vi /etc/ssh/sshd_config  修改为

# Authentication:
LoginGraceTime 120
PermitRootLogin prohibit-password
StrictModes yes

修改为

# Authentication:
LoginGraceTime 120
#PermitRootLogin prohibit-password
PermitRootLogin yes
StrictModes yes