本文保留屏幕亮度方法适合使用笔记本的朋友，大家都知道，过亮的屏幕不但刺眼而且缩短LCD屏幕寿命，不幸的是，Ubuntu默认关机后并不保存当前屏幕亮度配置数据，每次开机都要重新设置亮度，很不方便。本文介绍的方法可以彻底解决这个问题!

　　1.修改/etc/default/acpi-support

　　ENABLE_LAPTOP_MODE=true

　　2.修改 /etc/laptop-mode/laptop-mode.conf

　　交流电模式下使用 laptop mode

　　#

　　# Enable laptop mode when on AC power.

　　#

　　ENABLE_LAPTOP_MODE_ON_AC=1

　　#电池那也可设为1

　　使用 laptop mode 进行LCD亮度控制

　　#

　　# Should laptop mode tools control LCD brightness?

　　#

　　CONTROL_BRIGHTNESS=1

　　#

　　# Commands to execute to set the brightness on your LCD

　　#

　　BATT_BRIGHTNESS_COMMAND=”echo 0″

　　LM_AC_BRIGHTNESS_COMMAND=”echo 9″

　　NOLM_AC_BRIGHTNESS_COMMAND=”echo 9″

　　BRIGHTNESS_OUTPUT=”/sys/class/backlight/acpi_video1/brightness”

　　如果你不明白上面的设置的意思，可以参考下面的说明：

　　***********************************

　　# * If your system has the file “/proc/acpi/video/VID/LCD/brightness” (VID may

　　# be VID1 or similar), use this file as BRIGHTNESS_OUTPUT, and use

　　# the command “echo “. The possible values can be listed using the

　　# command: www.linuxidc.com

　　#

　　# cat /proc/acpi/video/VID/LCD/brightness

　　# * If you have a file /sys/class/backlight/…/brightness, then you can use

　　# that file as BRIGHTNESS_OUTPUT, and the command “echo “.

　　#

　　# As far as I understand it the values are between 0 and

　　# the value contained in the file /sys/class/backlight/…/max_brightness.

　　**********************************