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Accepted
LukeR
Asked: 2009-09-16 17:03:25 +0800 CST

ntpdate not updating system time in XenServer VM

  • 772

We have a Debian webserver that I am trying to use ntpdate to keep the time in sync.

When I run 

ntpdate ntp0.cs.mu.oz.au

I receive

16 Sep 10:55:36 ntpdate[21626]: step time server 128.250.36.2 offset 318.914011 sec

With no errors, which should be a good thing, I think...

When I check the time again though, it's not changed.

I am also unable to set the time manually using

date --set 11:00:00

So I have a feeling there are other issues.

Any advice would be appreciated.

Update

Sorry for the bum steer guys, this machine is a XenServer VM, which I managed to forget.

After updating the Host clock, the VM time is now correct.

Thanks for your replies. Thanks.

debian

5 Answers

  1. Best Answer

    I have been through this before.

    Try (on domU):

    echo 1 > /proc/sys/xen/independent_wallclock

    and try updating the time again.

    • 9

  2. Did the time change when you set the new time using date?

    Try and check the machine hardware clock. (man hwclock)

    • 1

  3. Try running ntpdate on an unprivileged port (in case you are running ntpd), otherwise it will refuse make any changes.

    ntpdate -u ntp0.cs.mu.oz.au
    • 1

  4. Try by this procedure:

    Stop the ntpd service first: 

    service ntpd stop

    Now update the local time

    ntpdate "server name"

    and after this start the service:

    service ntdp start
    • 1

  5. Have you given it time? Generally ntp will slowly adjust the time so when you look at logs things still make sense, and applications don't get messed up. This is called slewing, you can read about it in 'man ntpdate' or RFC 1305.

    "Time adjustments are made by ntpdate in one of two ways. If ntpdate determines the clock is in error more than 0.5 second it will simply step the time by calling the system settimeofday() rou‐ tine. If the error is less than 0.5 seconds, it will slew the time by calling the system adjtime() routine. The latter technique is less disruptive and more accurate when the error is small, and works quite well when ntpdate is run by cron every hour or two."

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