netcraft uptime

[Evren Yurtesen]

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