netcraft uptime

[Manolis Kiagias]

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, no sweat :)