panics on 24 hour boundaries
bv at wjv.com
Wed Oct 1 12:03:19 PDT 2003
On Wed, Oct 01, 2003 at 11:05 , Men gasped, women
fainted, and small children were reduced to tears as
freebsd-stable-request at freebsd.org confessed to all:
> Message: 18
> Date: Tue, 30 Sep 2003 23:19:34 -0400
> From: "Michael W. Oliver" <michael at gargantuan.com>
> Subject: Re: panics on 24 hour boundaries
[severly edited - wjv]
> +--- On Tuesday, September 30, 2003 22:35 ---
> | Robert Watson proclaimed:
> | Initial reactions: panics on 24 hour boundaries are, in my
> | experience, often associated with the daily event. Once a
> | day, the daily scripts run find several times on your file
> | systems, causing every file and directory to be inspected
> | for changes in setuid scripts, etc. This can trigger certain
> | classes of race conditions and resource limits that you might
> | otherwise not hit in normal operation -- and conviently, they
> | run 24 hours apart :-). To try and confirm this suspicion,
> | it would be interesting to know what time of day exactly the
> | panics take place, and whether you can reproduce the panic by
> | manually running the daily or security script.
> All of the panics happened in the evening hours, between 1800
> and 2200 EDT. I am also able to successfully run the daily
> periodic scripts at any time of the day without issue.
One part in this thread said the panics happened 24 hours after
reboot and that would imply something in scripts that depend upon
a length of time being powered up.
However if all the pnaics occur in the 1800-2200 time frame
this could be caused by an external event.
It could be any large device on the same electric circuits you are
on. By the 'same circuit' I mean anyone and/or anything connected
to the same power transformer. In a residential area this could be
Anything that could put a spike on the line could cuase this.
And even if the computer if filter and on a UPS if any device
connected to the computer is not also on the same filter those
could be the culprits. I've seen [in the far past when I
maintained many machines with serial terminal] terminals and also
printers cause this.
One place had contruction going on next door and that was alway
in early afternoon when one piece of equipment was fired up.
And one of the legendary stories is about the systems that paniced
every day between noon and about 10 after. That was traced to a
microwave in the lunchroom.
It's been my experience that often time related crashes are
external to the machines involved unless each and everything
connected to the machine is coming from the same filterer/protected
source, including all phone lines for DSL and or cable.
> End of freebsd-stable Digest, Vol 28, Issue 4
Bill Vermillion - bv @ wjv . com
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