Date: Thu, 13 Sep 2007 12:52:06 +0300 From: Evren Yurtesen <yurtesen@ispro.net> To: Manolis Kiagias <sonicy@otenet.gr> Cc: freebsd-questions@freebsd.org Subject: Re: netcraft uptime Message-ID: <46E90846.8030400@ispro.net> In-Reply-To: <46E8C301.5070309@otenet.gr> References: <46E86130.7060306@ispro.net> <46E8C301.5070309@otenet.gr>
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Manolis Kiagias wrote: > Evren Yurtesen wrote: > >> Hi, >> >> I see that netcraft uptime doesnt function because the kernel timer is >> set to 1000 by default in freebsd 6.x >> So perhaps setting kern.hz=100 fixes the problem? What about things >> getting wrapped in 497 days? How are there some FreeBSD hosts which >> have 1600+days uptime? how do they manage it? I am just trying to >> figure out how to do the same in my systems :) >> >> Thanks, >> Evren >> >> >> >> > > Yes, I believe the problem is the kernel timer. Older versions of > FreeBSD had a 100Hz timer. A Debian server of mine started showing > uptime again in Netcraft when I recompiled the kernel with 100Hz timer > setting. > As for the 497 days problem, I think this is Linux specific. I don't > know however if it will exist in FreeBSD 6.X with timer set to 100Hz. > Managing to get 1600 days uptime requires very solid hardware, possibly > with redundant (maybe hot swap) components and stable power. A UPS is > necessary and probably a generator, as during this time there is going > to be a blackout that will probably outlast your battery. FreeBSD is > actually the easiest (and less costly) part of the setup: It will, > simply, run all this time, From what I can see, the 32bit timer part used in TCP rolls over after 497 days. That is why they can not detect usage over 497 days. Netcraft says "Additionally HP-UX, Linux, NetApp NetCache, Solaris and recent releases of FreeBSD cycle back to zero after 497 days," > no sweat :) > Well, I could do over 500 days with a small ups and a 10 year old machine. There is almost no blackouts around here. When there is, it doesnt last more than 1-3 minutes once in 2-3 years. Anyway, we will see if netcraft will show 0 days after 497 but it would be a shame really :) Thanks, Evren
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