On Feb 19 10:12:03, Philip Guenther wrote:
> On Sun, Feb 19, 2012 at 6:17 AM, Jan Stary <h...@stare.cz> wrote:
> > On a recent install of current/i386 on an ALIX (see dmesg below),
> > processes (such as a simple 'ls') started to magically segfault and die.
> >
> > Feb 19 14:43:17 www /bsd: pid 26001 (bogofilter): user write of
> > 4096@0x3d5b000 at 1776 failed: 14
>
> 14 == EFAULT. Those are generated when the kernel tries to write out
> a process's memory image for a coredump and the indicated range of
> memory couldn't be faulted in so that it could be written to the
> filesystem.
>
Thank you for the explanation.
So, firstly, the kernel decides a proccess needs to be coredumped.
(That alone is a problem for me - why would that happen?)
And secondly, the attempt to coredump the process fails. Right?
> > What does this indicate? Is my RAM bad? Is my CF card bad?
> > Could someone more knowledgeable please explain the above
> > messages in detail?
>
> The inability to fault in memory that the kernel thinks should be
> there makes me wonder if you're swapping and the device you're
> swapping to is failing. Your dmesg suggests you might be swapping to
> your CF card and you (only?) have 128MB of real memory. When this is
> happening, what's the output of "swapctl -l"? If that shows you are
> indeed into swap, then a failing CF card would be my guess.
Yes, the machine only has 128MB of memory - which I think should be
enough for what it does: NATing pf, dhcpd and resolver for the
internal network, and postfix and httpd for my domain (which
amounts to almost no traffic).
It does not have any swap configured. In fact, I try to design
my systems so that they don't ever need to swap.
$ swapctl -l
swapctl: no swap devices configured
Would you please care to explain further how the swapping
is related to the coredumping EFAULTs?
> (Swapping to CF seems like a bad idea to me, but I'm not expert in
> that sort of hardware...)
I don't swap to the CF.
If it so happens that there is not enough memory for some running
process (a situaion I cannot rule out now), and there is no swap
to deal with this, is that a reason for a process to be coredumped?
(I think that I have seen processes just die with ENOMEM
in that situaion.)
Thank you for your time
Jan
