ntp returning future time

hi all,

ive noticed the time on a linux server im maintaining is set to 8 hours in the future.

i thought this was weird so i checked ntpd was on, and it is.

i thought this was even weirder so i checked the timezone,

$ ls -lah /etc/localtime
/etc/localtime -> /usr/share/zoneinfo/Australia/Brisbane

hmmm...

$ ntpdate -q 0.au.pool.ntp.org
server 119.148.81.6, stratum 2, offset -28768.189322, delay 0.06355
server 203.161.129.2, stratum 3, offset -28768.185683, delay 0.03165
server 202.158.218.239, stratum 3, offset -28768.187015, delay 0.04909
 8 Sep 19:49:49 ntpdate[16434]: step time server 119.148.81.6 offset -28768.189322 sec

uhh... totally wrong. i figured there might be some kind of catch in ntpd to not actually update the server time if it differed too greatly from the local time, so i set it manually:

$ date 090811492010
Wed Sep 8 11:45:00 EST 2010

then ran date again to see what happened:

$ date
Wed Sep 8 11:44:47 EST 2010

it went backwards 13 seconds! i figured ntpd had ran successfully and adjusted the server time, being 13 seconds incorrect.

subsequent checking of the date with ntpdate -q, though, still said 19:49 for the correct time, and as such ntpd reset the time to 19:49 within a matter of moments..

does anyone know what ive done wrong?

From serverfault mykchan

• Is this a dedicated virtual server, or a virtualized one? Some virtualization software can have a desync between the clocks on the host and guest OSs.

  mykchan : hmm... very good point. i didnt mention the server i was working on was virtualised. i bet the host os (xen) is configured wrong, and xentools is forcing the date on the guests. ill have a look and mark you correct if this is the case.

  mykchan : sadly, i havent had a chance to test this theory, as the host has the correct time. the guest now has the correct time too, however, so im pretty sure you were on the money.
  From Ryan Gooler