Date: Wed, 4 Dec 2013 13:28:51 -0800 From: Marc Fournier <scrappy@hub.org> To: Mikhail Tsatsenko <m.tsatsenko@gmail.com> Cc: freebsd-virtualization@freebsd.org Subject: Re: time drift w/virtualbox: FreeBSD Host -> FreeBSD guest w/ guest additions active Message-ID: <EA8A6B6F-08B3-40C0-A968-C1BD57E748A6@hub.org> In-Reply-To: <CAGK=9AHSX_E-CuUNGZcu7nEksoDpoFX=0dcjZyxHd1nySECTAg@mail.gmail.com> References: <059857EF-534E-4366-BD11-924AB3ED7C31@openstudent.ca> <CAGK=9AHSX_E-CuUNGZcu7nEksoDpoFX=0dcjZyxHd1nySECTAg@mail.gmail.com>
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Done: =3D=3D=3D :~ # sysctl kern.eventtimer.idletick=3D1 kern.eventtimer.idletick: 0 -> 1 :~ # ntpdate time.nist.gov 4 Dec 14:02:11 ntpdate[30137]: step time server 128.138.141.172 offset = 239.820647 sec :~ #=20 =3D=3D=3D And, already 6 secs off: # ssh ruralcatholicradio.com date ; date Wed Dec 4 14:03:09 EST 2013 Wed Dec 4 19:03:15 UTC 2013 On Dec 4, 2013, at 10:50 , Mikhail Tsatsenko <m.tsatsenko@gmail.com> = wrote: > 2013/12/4 Marc Fournier <mfournier@openstudent.ca>: >>=20 >> Why is this such a difficult thing to keep in sync? :( >>=20 >> I have a FreeBSD Host running 4.2.18 =85 Guest FreeBSD Host has = Additions 4.2.18 installed .. >>=20 >> On the Host, I believe all the kernel modules are loaded properly: >>=20 >> # kldstat|grep vb >> 6 3 0xffffffff80c59000 59da0 vboxdrv.ko >> 8 2 0xffffffff80e20000 29f1 vboxnetflt.ko >> 11 1 0xffffffff80e2e000 3f8a vboxnetadp.ko >>=20 >> On the Guest, again, I believe everything is loaded: >>=20 >> # kldstat|grep vb >> 2 1 0xffffffff80c12000 26585 vboxguest.ko >>=20 >> And the VB processes are started: >>=20 >> # ps aux | grep VB >> root 606 0.0 0.1 32244 2144 ?? Ss 6:06PM 2:09.26 = /usr/local/sbin/VBoxService >>=20 >> I don=92t have ntpd running on the Guest, but have tried it with it = running also ... >>=20 >> But, my time is already drifting: >>=20 >> # ssh ruralcatholicradio.com date ; date >> Wed Dec 4 12:01:34 EST 2013 >> Wed Dec 4 17:03:17 UTC 2013 >>=20 >> So, I login and run ntpdate to bring it back in sync: >>=20 >> # ntpdate time.nist.gov >> 4 Dec 12:04:02 ntpdate[71827]: step time server 66.219.116.140 offset = 102.233151 sec >>=20 >> Note that the below is run from the FreeBSD Host that the Guest is = running on =85 same physical machine =85 we are perfectly in sync: >>=20 >> # ssh ruralcatholicradio.com date ; date >> Wed Dec 4 12:04:32 EST 2013 >> Wed Dec 4 17:04:32 UTC 2013 >>=20 >> An hour later, we=92ve now drifted by almost 2 minutes: >>=20 >> # ssh ruralcatholicradio.com date ; date >> Wed Dec 4 13:07:18 EST 2013 >> Wed Dec 4 18:09:16 UTC 2013 >>=20 >>=20 >> Its hard to believe that anyone would be using VirtualBox if it time = drifted like this regularly, so I figure it has to be something that I=92m= doing wrong in my configuration =85 >>=20 >>=20 >> Thoughts? > Please try setting sysctl kern.eventtimer.idletick=3D1 on the guest = machine. >=20 > --=20 > Mikhail
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