我在使用ubuntu11.04的時候，爲了配置hadoop，使用root用戶修改主機名:
gedit /etc/hostname;
gedit /etc/hosts;
修改的時候出現以下錯誤
我在使用gedit打開文件的時候，會提示一堆的警告：
(gedit:9778): Gtk-WARNING **: Attempting to store changes into `/root/.local/share/recently-used.xbel', but failed: Failed to create file '/root/.local/share/recently-used.xbel.LTBP3V': No such file or directory
(gedit:9778): Gtk-WARNING **: Attempting to set the permissions of `/root/.local/share/recently-used.xbel', but failed: No such file or directory
(gedit:9778): Gtk-WARNING **: Attempting to store changes into `/root/.local/share/recently-used.xbel', but failed: Failed to create file '/root/.local/share/recently-used.xbel.47P63V': No such file or directory
(gedit:9778): Gtk-WARNING **: Attempting to set the permissions of `/root/.local/share/recently-used.xbel', but failed: No such file or directory
(gedit:9778): Gtk-WARNING **: Attempting to store changes into `/root/.local/share/recently-used.xbel', but failed: Failed to create file '/root/.local/share/recently-used.xbel.MN6R3V': No such file or directory
(gedit:9778): Gtk-WARNING **: Attempting to set the permissions of `/root/.local/share/recently-used.xbel', but failed: No such file or directory
根據上面的提示，以及網上查的資料，知道的怎麼解決：
直接在terminal中輸入 sudo mkdir -p /root/.local/share/
也就是表示以超級用戶（sudo命令）身份創建目錄