Date: Mon, 19 Mar 2012 13:20:35 +0700 From: Adam Strohl <adams-freebsd@ateamsystems.com> To: Steve Wills <swills@FreeBSD.org> Cc: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>, FreeBSD-Stable ML <freebsd-stable@FreeBSD.org> Subject: Re: Time Clock Stops in FreeBSD 9.0 guest running under ESXi 5.0 Message-ID: <4F66D033.9050103@ateamsystems.com> In-Reply-To: <4F662B38.4030700@FreeBSD.org> References: <4F5B0BB5.5010406@ateamsystems.com> <6D0B99CE-AE11-4250-A8D9-EF66E03E19BB@lists.zabbadoz.net> <4F5B5DAB.3010905@ateamsystems.com> <4F662B38.4030700@FreeBSD.org>
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On 3/12/2012 0:01, Ian Lepore wrote: > It seems unlikely to me that ntpd and the vm tools would be fighting in > a way that caused this symptom. The way ntpd affects timing is to step > the clock (which gets logged), or to numerically steer the kernel's > timekeeping routines. The steering is clamped at 500 ppm; to make the > clock appear to stop it would have to steer at 1e6 ppm. I've always > assumed that VM guest services daemons that handle timekeeping use the > same ntp_adjtime() interface to the kernel timekeeping that ntpd itself > uses, so the same steering limits would apply. An excellent point. > > If it happens again, interesting data might be found in the output of: > > sysctl kern.timecounter > sysctl kern.eventtimer > vmstat -i > ntpdc -c kerninfo > <anything unusual in dmesg output> Will do, I know there was nothing in dmesg, I will definitely check all of this though if/when it happens again. I just brought up another ESXi 5.0 host with FreeBSD 9.0 VMs (created from dump/restore from the existing ones), so there is an increased chance of me seeing this hopefully and getting to the bottom of it. Or it never happens again :P On 3/19/2012 1:36, Steve Wills wrote: > I've experienced something similar once or twice with ESXi 5.0. The > second time it happened, I found that kern.timecounter.tc.HPET.counter > stopped changing. I was told on IRC that this indicated a "hardware" > problem, which I took to indicate a possible bug in ESXi. I haven't > upgraded to ESXi 5.0 Update 1 yet to see if that changes anything. > Rebooting of course fixed it, it has been a while since this happened > and it hasn't happened again since so I haven't pursued it. Just another > data point, hope it hopes. Thanks for the info! I didn't realize there was an update out already for 5.0 (I don't see it on VMWare's site).
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