I've had all my systems syncing via ntp for a long time.
But since the karmic ugrade my clock has not stayed in sync.

I turned off ntp. And ended up writing a little bash script:

while true; do sudo ntpdate 0.pool.ntp.org; sleep 600; done

It produces the following output.

15 Nov 07:11:41 ntpdate[7129]: step time server 207.171.30.106 offset
-7.265514 sec
15 Nov 07:21:35 ntpdate[7215]: step time server 128.10.252.9 offset
-7.267561 sec
15 Nov 07:31:30 ntpdate[7334]: step time server 74.207.245.227 offset
-7.279796 sec
15 Nov 07:41:24 ntpdate[7862]: step time server 74.207.245.227 offset
-7.257386 sec
15 Nov 07:51:19 ntpdate[7927]: step time server 128.10.252.6 offset
-7.280644 sec
15 Nov 08:01:13 ntpdate[8002]: step time server 69.63.177.217 offset
-7.262078 sec
15 Nov 08:11:08 ntpdate[8052]: step time server 155.101.3.114 offset
-7.277998 sec
15 Nov 08:21:02 ntpdate[8222]: step time server 204.9.54.119 offset
-7.263816 sec
15 Nov 08:30:56 ntpdate[8348]: step time server 204.9.54.119 offset
-7.268109 sec
15 Nov 08:40:51 ntpdate[8450]: step time server 74.207.245.227 offset
-7.275060 sec
15 Nov 08:50:45 ntpdate[8497]: step time server 174.133.44.162 offset
-7.276354 sec
15 Nov 09:00:41 ntpdate[8575]: step time server 216.129.104.26 offset
-7.271786 sec
15 Nov 09:10:36 ntpdate[8631]: step time server 69.63.177.217 offset
-7.293453 sec
15 Nov 09:20:30 ntpdate[8814]: step time server 128.10.252.6 offset
-7.264526 sec

ntp can't fix a clock that is off by more than 7.25 seconds every 10 minutes.

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drew einhorn wrote:
>
>
> ntp can't fix a clock that is off by more than 7.25 seconds every 10 minutes.
>

what is the output of:


sudo cat /sys/devices/system/clocksource/clocksource0/current_clocksource

and:

sudo cat /sys/devices/system/clocksource/clocksource0/available_clocksource

I'm betting your current clocksource is tsc, which the kernel seems to
favor as default on some systems, but just doesn't keep track of time
all that well.

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On Sun, Nov 15, 2009 at 1:54 PM, Rashkae <ubuntu@tigershaunt.com> wrote:

drew einhorn wrote:

>

>

> ntp can't fix a clock that is off by more than 7.25 seconds every 10 minutes.

>



what is the output of:





*sudo cat /sys/devices/system/clocksource/clocksource0/current_clocksource



tsc
*
and:



sudo cat /sys/devices/system/clocksource/clocksource0/available_clocksource



tsc acpi_pm


I'm betting your current clocksource is tsc, which the kernel seems to

favor as default on some systems, but just doesn't keep track of time

all that well.
Bingo!

Now that we know what's wrong.* How do we fix it?

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drew einhorn wrote:
> On Sun, Nov 15, 2009 at 1:54 PM, Rashkae <ubuntu@tigershaunt.com> wrote:
>
>> drew einhorn wrote:
>>>
>>> ntp can't fix a clock that is off by more than 7.25 seconds every 10
>> minutes.
>> what is the output of:
>>
>>
>> sudo cat /sys/devices/system/clocksource/clocksource0/current_clocksource
>>
>>
> tsc
>
>
>> and:
>>
>> sudo cat /sys/devices/system/clocksource/clocksource0/available_clocksource
>>
>>
> tsc acpi_pm

> I'm betting your current clocksource is tsc, which the kernel seems to
>> favor as default on some systems, but just doesn't keep track of time
>> all that well.
>>
>
> Bingo!
>
> Now that we know what's wrong. How do we fix it?
>
>

Append clocksource=acpi_pm to your kernel options. If you have Grub 2,
you would edit one of the default files in /etc/grub, then run
grub-update. However, since you indicated an upgrade, you might still
have Grub-legacy, (wherin you edit the /boot/grub/menu.lst file)

I would also encourage people with this issue to file a bug in
Launchpad. I was hit by this with my gutsy system, but now you're the
second person I've noticed on the list to be affected by this with Karmic.



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On Sun, Nov 15, 2009 at 3:10 PM, Rashkae <ubuntu@tigershaunt.com> wrote:
*

I would also encourage people with this issue to file a bug in

Launchpad. *I was hit by this with my gutsy system, but now you're the

second person I've noticed on the list to be affected by this with Karmic.
*It's bug #483316
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> Append clocksource=acpi_pm to your kernel options. *If you have Grub 2,
> you would edit one of the default files in /etc/grub, then run
> grub-update. *However, since you indicated an upgrade, you might still
> have Grub-legacy, (wherin you edit the /boot/grub/menu.lst file)

For GRUB legacy, you can add clocksource=acpi_pm to defoptions (for
"normal" entries) or altoptions (for all entries) and then run
update-grub. You will then not have to re-edit menu.lst when your
kernel is upgraded to add clocksource=acpi_pm to your kernel lines.

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