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I would like to run the following command after every boot (or login).

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

It turns off my discrete GPU. To what script should I add this command. I would appreciate any help.

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Looks about the same as the first related question: – TLP Oct 16 '11 at 17:15

Instead of running a script you could install the package sysfsutils and add the line


to the file /etc/sysfs.conf

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that did it. thanks all :) – Garips Oct 16 '11 at 17:40

You need root privileges to run that command, so you can add it to /etc/rc.local (but before the exit 0 line) to have it run at the end of the boot process.

Otherwise you can add it to /etc/gdm/PostLogin/Default to have it run after any graphical login (when using GNOME GDM, default for Ubuntu before 11.10). If the file does not exist, just rename /etc/gdm/PostLogin/Default.sample and edit it.

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i did that, but it doesn't work. I also tried to put "sleep 10" before the command, because i read somewhere it could be executed too early. do I just need to add the above mentioned line or is there more to it? – Garips Oct 16 '11 at 17:17
@Garips you might want to check and confirm that you have the necessary options enabled in the kernel and that the /sys/kernel/debug filesystem is mounted... – Riccardo Murri Oct 16 '11 at 17:23
does the /etc/gdm/PostLogin/Default work with 11.10 ? – Garips Oct 16 '11 at 17:24
@Garips Likely not, as 11.10 is using LightDM, not GDM – Riccardo Murri Oct 16 '11 at 17:26
i think the options should be enabled, otherwise the command would't work at all. but it does work when I run it manually in the terminal. – Garips Oct 16 '11 at 17:27

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