[Sugar-devel] Clocks on XOs
bernie at codewiz.org
Sat Jul 3 09:54:16 EDT 2010
El Fri, 02-07-2010 a las 20:15 -0700, Hal Murray escribió:
> Is that one of the old XOs that had troubles with the tiny battery feeding
> the TOY/RTC clock when the main battery and wall power are both disconnected?
> I forget the details, but I think there was a problem with the battery
Likely so, but the software should be able to compensate for it. After
discussing it on IRC, it seems that olpc-update-query should
automatically update the clock from the OATS server.
> NetworkManager used to call ntpdate when it setup a connection. Was that an
> OLPC addition?
We figured out that the ntp package has never been present on the XO
> I think this area gets tangled up with security and lease checking. Do we
> want/need two separate modes, one for the secure case and another for
> developers without a school server?
We discussed the security implications of using unauthenticated ntp on
XOs with anti-theft enabled yesterday on IRC. The concern is that a
clever thief could setup a LAN with DHCP, DNS and NTP to set a date in
te past and thus subvert the leases expiration scheme.
However, with root access on the laptop, one does not need to bother so
much: they could simply change the time from the console or, better,
There's no way to practical way to implement effective anti-theft
without taking away root from the user. And once we take away root
access, we've also taken away olpc's principle #1: child ownership.
> What are the school servers doing to keep their clocks reasonable?
They're using ntp, with the Fedora pool of ntp servers.
> > Why aren't we using ntp?
> ntp is probably overkill for XOs. Besides, who would want to give up that
> much ram? On top of that, ntpd doesn't get along with power saving mode.
Wow, 2MB of RSS! I had no idea ntp was such a hog.
> Aside from quirks like this one, is time on the XO normally good enough?
I would have to check...
// Bernie Innocenti - http://codewiz.org/
\X/ Sugar Labs - http://sugarlabs.org/
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