Date: Wed, 29 Aug 2012 09:00:55 +0200 (CEST) From: Richard Kojedzinszky <krichy@tvnetwork.hu> To: freebsd-xen@freebsd.org Subject: Re: time jumps in xen amd64/hvm instance Message-ID: <alpine.DEB.2.02.1208281207460.23562@krichy.tvnetwork.hu> In-Reply-To: <alpine.DEB.2.02.1208131000540.28956@krichy.tvnetwork.hu> References: <alpine.DEB.2.02.1207092107420.23515@krichy.tvnetwork.hu> <alpine.DEB.2.02.1207102055340.28514@krichy.tvnetwork.hu> <alpine.DEB.2.02.1208131000540.28956@krichy.tvnetwork.hu>
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Dear Xen users, After some experiencing, I've found a soultion to my problem, I just share it with you, and hope you wont get issues that I got. Maybe, all experience is just true for my hardware, but it is not a special one, it is a Supermicro PDSMi-LN4 board with a Q6700. I think other parameters do not affect. I had problems with time skews in the domU's, particularly with freebsd systems. With HVM instances, hpet should be enabled for the vm, as it keeps time ticking very precise. But I had issues, that caused time jumps in a short time, and I've found it was related to the dom0's kernel message 'Clocksoure tsc unstable'. So then, I've started my xen hypervisor with clocksource=pit, and since then (around 1 week) I do not experience such time jumps, or time skews. Regards, Kojedzinszky Richard Euronet Magyarorszag Informatikai Zrt. On Mon, 13 Aug 2012, Richard Kojedzinszky wrote: > Date: Mon, 13 Aug 2012 10:08:29 +0200 (CEST) > From: Richard Kojedzinszky <krichy@tvnetwork.hu> > To: freebsd-xen@freebsd.org > Subject: Re: time jumps in xen amd64/hvm instance > > Dear developers/users, > > I am still facing with time jump problems. Did somebody detect same issues, > or only I am doing something wrong. My dom0 is a debian squeeze, my domU is a > freebsd-9.0, amd64, kernel compiled by myself. > > Currently I cannot find the exact steps needed to reproduce the problem, but > unfortunately it happens. Actually, in the past weekend it did also, when the > server had lower load than in workdays. > > Where should I look further? Any ideas? > > Thanks, > > Kojedzinszky Richard > Euronet Magyarorszag Informatikai Zrt. > > On Tue, 10 Jul 2012, Richard Kojedzinszky wrote: > >> Date: Tue, 10 Jul 2012 20:57:09 +0200 (CEST) >> From: Richard Kojedzinszky <krichy@tvnetwork.hu> >> To: freebsd-xen@freebsd.org >> Subject: Re: time jumps in xen amd64/hvm instance >> >> >> just an update, as I remember, this happened to 8.2 bsd in paravirtualized >> mode also. >> >> >> Kojedzinszky Richard >> Euronet Magyarorszag Informatikai Zrt. >> >> On Mon, 9 Jul 2012, Richard Kojedzinszky wrote: >> >>> Date: Mon, 9 Jul 2012 21:10:52 +0200 (CEST) >>> From: Richard Kojedzinszky <krichy@tvnetwork.hu> >>> To: freebsd-xen@freebsd.org >>> Subject: time jumps in xen amd64/hvm instance >>> >>> Dear Xen users, >>> >>> I have a strange problem, my hvm instance sometimes jumps time forward. I >>> made a little script to monitor this, and I am attaching its result also. >>> I have no clues where to look, why this jump happens, but of course it is >>> not normal. And as I have kern.securelevel at 2, ntp cannot correct this. >>> >>> Could somebody help? >>> >>> The amd64hvmntp.sh script is run by cron every minute. >>> >>> Thanks in advance, >>> >>> Kojedzinszky Richard >>> Euronet Magyarorszag Informatikai Zrt. >> _______________________________________________ >> freebsd-xen@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-xen >> To unsubscribe, send any mail to "freebsd-xen-unsubscribe@freebsd.org" >> > _______________________________________________ > freebsd-xen@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-xen > To unsubscribe, send any mail to "freebsd-xen-unsubscribe@freebsd.org" >
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