ubuntu在recovery模式下更改用户密码

http://www.jb51.net/os/Ubuntu/164636.html

1, restart

2, Hold down shift key / press and hold

3, select "recovery mode"

4, select "root      Drop to root shell prompt"

5, check username : cat /etc/shadow

6, :passwd "username"

error: c“-passwd：Authenticationtoken manipulation error“

reason: recovery mode is read-only filesystems, 

check authority : lsattr /etc/shadow

solution: change file systems authority : mount / -o rw,remount