[Planetlab-users] NTP daemon

[Neil Spring]

There's one listed by comon that is three days ahead of us all.  I  
wonder what it knows about sigcomm submissions...

http://comon.cs.princeton.edu/status/

Use ntptrace to check how planetlab machines sync (or don't) time.

kohoutek:~% ntptrace planetlab2.nbgisp.com
planetlab2.nbgisp.com: stratum 16, offset 0.000000, synch distance  
65.270880

kohoutek-2:~% ntptrace planetlab2.inf.ethz.ch
planetlab2.inf.ethz.ch: stratum 16, offset 0.000000, synch distance  
60.941625

kohoutek-2:~% ntptrace salt.planetlab.cs.umd.edu
salt.planetlab.cs.umd.edu: stratum 3, offset -0.002568, synch distance  
0.105086
gallifrey.chpc.utah.edu: stratum 2, offset 0.000460, synch distance  
0.052654
time-C.timefreq.bldrdoc.gov: stratum 1, offset 0.000000, synch  
distance 0.002650, refid 'ACTS'

-neil

On Jan 30, 2008, at 11:18 AM, Alex Sherman wrote:

> Speaking of NTP I consistently see some machines with several  
> minutes to
> an hour drift compared to the rest of the machines that are  
> typically in
> sync:
>
> planetlab2.inf.ethz.ch (-10 minutes)
> planetlab3.inf.ethz.ch (-10 minutes)
> planetlab2.ukc.ac.uk (+ 55 minutes)
>
> Are these talking to an NTP server ?
>
> thanks
> -Alex
>
>
> On Wed, 2008-01-30 at 01:34 -0500, Neil Spring wrote:
>> Markus,
>>
>> NTP is already running on planetlab... believe it or not.
>>
>> You may be able to run some of the ntp tools (e.g., ntptrace) on
>> planetlab to figure out what the running daemon thinks.
>>
>> (Even if ntp weren't already running, you would need permission to
>> bind the privileged port 123.  I don't *think* there's a way to run  
>> an
>> NTP server on a different port, but you might look into it.)
>>
>> -neil
>>
>> On Jan 29, 2008, at 5:30 PM, Markus Gnauck wrote:
>>
>>> Hello PlanetLab Users!
>>>
>>> I installed ntp on some of my project's nodes. Unfortunately when
>>> trying to run the ntp service it seems to crash immediately upon
>>> startup.
>>>
>>> $ sudo yum install ntp
>>> ..works as expected..
>>>
>>> $ sudo /etc/init.d/ntpd start
>>> Starting ntpd:                                             [  OK  ]
>>>
>>> $ /etc/init.d/ntpd status
>>> ntpd dead but pid file exists
>>>
>>> I tried to search for the problem, with some sources suggesting to
>>> delete /var/run/ntpd.pid and restarting ntpd. As anticipated that
>>> did not help much. The results are still as depicted above. (To my
>>> knowledge the configuration file ntpd.conf seems fine though.)
>>>
>>> When tracing the problem my tutor came up with the following output
>>> which strongly seems like a permission issue:
>>>
>>> Jan 27 18:42:54 chronos ntpd[31596]: ntpd 4.2.0a at 1.1196-r Fri May 12
>>> 09:51:35 EDT 2006 (1)
>>> Jan 27 18:42:54 chronos ntpd[31596]: Cannot set RLIMIT_MEMLOCK:
>>> Operation not permitted
>>> Jan 27 18:42:54 chronos ntpd[31596]: mlockall(): Cannot allocate
>>> memory
>>> Jan 27 18:42:54 chronos ntpd[31596]: precision = 1.000 usec
>>> Jan 27 18:42:54 chronos ntpd[31596]: bind() fd 4, family 2, port  
>>> 123,
>>> addr 0.0.0.0, in_classd=0 flags=8 fails: Permission denied
>>> Jan 27 18:42:54 chronos ntpd[31596]: bind() fd 4, family 2, port  
>>> 123,
>>> addr 127.0.0.1, in_classd=0 flags=0 fails: Permission denied
>>> Jan 27 18:42:54 chronos ntpd[31596]: bind() fd 4, family 2, port  
>>> 123,
>>> addr 134.34.246.5, in_classd=0 flags=8 fails: Permission denied
>>> Jan 27 18:42:54 chronos ntpd[31596]: bind() fd 4, family 2, port  
>>> 123,
>>> addr 134.34.246.5, in_classd=0 flags=8 fails: Permission denied
>>> Jan 27 18:42:54 chronos ntpd[31596]: bind() fd 4, family 2, port  
>>> 123,
>>> addr 10.41.221.1, in_classd=0 flags=8 fails: Permission denied
>>> Jan 27 18:42:54 chronos ntpd[31596]: kernel time sync status 0040
>>> Jan 27 18:42:54 chronos ntpd[31596]: cap_set_proc() failed to drop
>>> root
>>> privileges: Operation not permitted
>>>
>>> The problem appeared on all the nodes that I've considered. I'm kind
>>> of at a loss right now. Do you have any suggestions, pointers or
>>> help to solve my problem?!
>>> Please let me know if I better direct the question to a different
>>> source of support for issues regarding PlanetLab.
>>>
>>> Thanks in advance! Cheers,
>>> -Markus
>>>
>>> _______________________________________________
>>> Users mailing list: Users at lists.planet-lab.org
>>> https://lists.planet-lab.org/mailman/listinfo/users
>>
>> _______________________________________________
>> Users mailing list: Users at lists.planet-lab.org
>> https://lists.planet-lab.org/mailman/listinfo/users