Subject: booting laptops on battery power vs. the clock
To: None <>
From: Steven M. Bellovin <>
List: netbsd-users
Date: 09/26/2007 18:45:25
I had an incident the other day where my machine couldn't keep time --
despite running ntpd, the clock was running very fast.  Restarting ntpd
after running ntpdate and removing /var/db/ntp.drift didn't help.  I
finally rebooted.

It occurred to me, though, that the last reboot had been done when
running on battery power.  BSD/OS used to have problems like that; it
would get the clock frequency wrong.  

I'm running 4.99.31 on a Thinkpad.  Sysctl shows

	kern.timecounter.hardware = i8254

but that's auto-set.  Estd is running.  Ntpq shows that the new ntpds
do indeed establish associations with outside time servers.  I've seen
a similar symptom on a 4.0rc2 laptop, though I don't have full details
about its past reboot.


		--Steve Bellovin,