This time it worked! However, there was some unexpected behavior, so I have follow-up questions...
When I arrived at my computer this morning, it was asleep. Thus, I first though that the wake timer fix had not worked, and that the scheduled backup had not run. However, upon manually waking the laptop and examining logs, I found that the backup did
run on schedule (36 seconds after the computer was woken out of S3 sleep), and completed 67 seconds later. The unexpected behavior was that 101 seconds after the backup completed, there was an Event 42 indicating that the system was entering sleep, stating "Sleep Reason: System idle." I was surprised by this, because my custom power plan specifies that the computer should never go to sleep or even turn off its display (it does
specify to turn off hard disk after 60 min of inactivity, but I'm not sure if this even applies to an SSD).
After researching this behavior, I found that there is an additional, hidden setting for the advanced power configuration, which can be revealed by typing the following command in an elevated PowerShell window (hat tip to user jenae at techsupportforum.com
powercfg -attributes SUB_SLEEP 7bc4a2f9-d8fc-4469-b07b-33eb785aaca0 -ATTRIB_HIDE
After executing the above command, settings for System unattended sleep timeout
will be available under the Sleep
node in the advanced power settings. The tool tip pop-up clarifies that these settings represent "Idle timeout before the system returns to a low power sleep state after waking unattended"; the default value is 2 min (for when on battery power and when plugged in). So this seems to explain why the computer resumed sleep after being woken by the Macrium Scheduler.Follow-up Questions:
- Although this morning's behavior seems to make sense now, the timing of events is not perfectly consistent with the default 2-min setting for the System unattended sleep timeout. The sleep state was resumed 101 seconds (< 2 min) after the Reflect backup was completed, which was 204 seconds (> 3 min) after the wake-up call. I can accept that maybe "2 min" doesn't necessarily mean exactly 2 min, but I'd like to know when does it start counting (i.e., what constitutes "idle" for the purposes of this timer?)? Is the computer considered "idle" as long as there is no human input? Or is it considered "idle" only if the backup job has completed (and there are no further scheduled tasks or human inputs)?
- If the "idle" timer starts as soon as the computer wakes up (and keeps ticking as long as there is no human input), is there a risk that this System unattended sleep timeout event could interrupt/terminate the running Reflect backup task?
- Bottom line question: Do I need to make sure that the System unattended sleep timeout settings are sufficiently long to guarantee that the scheduled backup can be completed before the system is put back to sleep?