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Sleep & Wakeup Schedule | Ubuntu 16.04.3 LTS
March 5, 2018
Edited: June 12, 2020
November 24, 2022
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The script you are following is overly complicated. A simpler method is described here.
Before a full implementation of 1am sleep and 6am wake, you can do a simple 10 second test:
sudo rtcwake -m mem -s 10 && firefox
This test will ensure suspending to RAM actually works. Upon resuming
firefox is automatically started up.
Rather than messing around with UTC, have your
rtcwake command called from
cron at 1am and wake up
18000 seconds later. Your cron table entry would look something like this:
0 1 * * * sh /usr/sbin/rtcwake -m mem -s 18000 >> /home/Me/SuspendResume.log 2>&1
There is no need for
sudo prefix because
cron runs with sudo privileges.
Me with your user name. Check the file
SuspendResume.log for cron messages periodically and whenever there is a problem.
2>&1 option redirects error messages to the
- RTC stands for real-time clock. rtcwake uses your computer’s hardware clock, which you can set in your BIOS, to determine when your computer will wake up. If you’re using an old computer with a dying CMOS battery that can’t keep the clock running properly, this won’t work.
- If sleep, suspend to RAM, or hibernate don’t work properly with your Linux system – perhaps because Linux doesn’t have the drivers to make them work properly with your hardware – this may not work.
- Be careful when setting a laptop to automatically wake at a specific time. You wouldn’t want it waking up, running, and overheating or running down its battery in a laptop bag.