I'm having an assignment where the lecturer is asking me to create a bash script to shut down a server at 11pm and turn it on at 6am. I'm able to do it by using sudo shutdown -h 23:00 and it works. But the problem is that I have no idea how to turn it on automatically on 6am, I couldn't find any commands that could do that. Any help would be appreciated.
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Are you sure your assignment asks you to turn off the whole machine (and back on again), or just one server process? Obivously, the physical machine needs to be switched on to do anything.– JosMar 24, 2014 at 15:32
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To be honest, I have no idea too, I also thought this would be impossible. The lecturer is being very vague on the assignment brief and its driving me nuts as well.– JLWKMar 24, 2014 at 16:57
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1 Answer
First you need to check if you can use the RTC wakealarm to wake your system:
sudo sh -c "echo 0 > /sys/class/rtc/rtc0/wakealarm"
sudo sh -c "echo `date '+%s' -d '+ 3 minutes'` > /sys/class/rtc/rtc0/wakealarm"
cat /sys/class/rtc/rtc0/wakealarm
Now check:
cat /proc/driver/rtc
This should return a list of parameters. Check the alrm_time is 3 minutes into the future and the alrm_date is today.
If it works ok, create a /usr/local/sbin/shutwake script:
#!/bin/bash
sh -c "echo 0 > /sys/class/rtc/rtc0/wakealarm"
sh -c "echo `date '+%s' -d '+ 7 hours'` > /sys/class/rtc/rtc0/wakealarm"
shutdown -h now
Finally edit your user crontab, type crontab -e and add the following line:
0 23 * * * /usr/local/sbin/shutwake
answered Mar 24, 2014 at 15:49
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I depends on BIOS clock settings, check
/etc/default/rcSto see if UTC is set or not. Mar 24, 2014 at 16:59 -
Well, I tried exactly the same what you wrote above. It didn't worked:(. -Debian 8 Aug 1, 2016 at 12:21