ubuntu修改grub開機時間

here:
/etc/default/grub

after modified should be updated:

update-grub

xeyes X11 connection rejected because of wrong authentication. Error: Can't open display: localhost:11.0

發現X11 connection有問題，原來是我變成"su"之後執行指令就產生以下訊息：
xeyes X11 connection rejected because of wrong authentication. Error: Can't open display: localhost:11.0


解法：

An easier solution follow as:
1.- ssh user@host

2.- $ sudo su

3.- # xauth merge /home/user/.Xauthority