[ltp] cron vs. suspend (was: suspend resume works fine for sh ort suspends - fails for longer suspends)

Ivarsson, Torbjorn (T) linux-thinkpad@linux-thinkpad.org
Tue, 6 Apr 2004 09:51:21 -0500


> -----Original Message-----
> From: Tino Keitel [mailto:tino.keitel@gmx.de]
> Sent: Tuesday, April 06, 2004 9:17 AM
> 
> > It seems like this cron-wakeup may be partly responsible for the
> > hang-up. I was under the impression that a suspend-to-RAM (APM) will
> > stop most of the activities in the computer, but I guess I had the
> > wrong impression...
> 
> No, you are right. Per definition, during suspend to RAM, the machine
> is nearly switched off compelely. At least the operating 
> system doesn't
> run anymore. Only the RAM has power so it doesn't lose its content. On
> my A30, the little moon light will light up during suspend to RAM.

So why am I seeing a cron message at 01:00 everyday in my /var/log/syslog looking something like this when my laptop has been suspended at that time?

  Apr 5 01:00:00 localhost CROND[6420]: (root) CMD (nice -n 19 run-parts /etc/cron.daily)

(The example is fabricated, I'm at work right now. I can supply full log tomorrow.)

If cron is not waking up a "apm --suspend" to run its daily task (note: cron.hourly is not run), the only other reason I can see would be that I am not fully suspended.

If the OS doesn't run anymore, that means that the only way to wake up the computer is by some external action (open lid, press button, etc.), right?

I must say that these power management topics are fascinating and frustrating all at the same time... :)

T.