故障

yeqiang@yeqiang-PC:~$ su -s /bin/bash nobody
请输入密码:
验证成功
su: using restricted shell /usr/sbin/nologin
This account is currently not available.
yeqiang@yeqiang-PC:~$ 

解决，采用root权限切换

yeqiang@yeqiang-PC:~$ sudo su -s /bin/bash nobody
请输入密码:
验证成功
nobody@yeqiang-PC:/home/yeqiang$ whoami
nobody
nobody@yeqiang-PC:/home/yeqiang$ 

注意，此处输入的是yeqiang的密码，且yeqiang具备root组权限