Re: Constant coredumps

[Todd Gruhn <tgruhn2%gmail.com@localhost>]

Another user pointed out they had problems with
core-dumps and USB. The pointed out the problem was
the USB hub. I disconnected my USB hub; the problem
went away.

What does a USB-hub have to do with a core-dump?

On Tue, Mar 1, 2022 at 5:59 PM <ignatios%cs.uni-bonn.de@localhost> wrote:
>
> hello,
>
> On Mon, Feb 28, 2022 at 10:50:00AM -0500, Todd Gruhn wrote:
> > I noticed that every time I   start NetBSD I get a message that says
> > it compressing netbsd.core.
> >
> > Why is this happening? Has anyone noticed this?
>
> Every time? how many files are in /var/crash? what do
>
> df -h /var/crash
> and
> du -h /var/crash
> show?
>
> Normally, this means that every time you're booting, the system finds
> the signature of a system core dump in the swap partition.
>
> In this case, one of the startup files will save the coredump from
> the dump partiton - normally the (first) swap partion - to the filesystem,
> and save the (compressed) current kernel alongside, so that somebody could
> use both to find out what the problem is.
>
> This either means that you always reboot by crashing the NetBSD
> kernel, or that the filesystem /var/crash is on is too small to
> add your core dump and your compressed kernel, so this never
> finishes.
>
> By looking at the answer to my above questions, you can distinguish the
> cases.
>
> If you don't intend to debug an old kernel crash, you can get rid of
> it by running
>
> /sbin/savecore -c
>
> with swap disabled, e.g. in single user mode, or after
> swapctl -d /dev/yourdumpdevice
>
> check for your dump device by
>
> grep dumps /var/run/dmesg.boot
>
> It should look similar to this:
>
> $ grep dump /var/run/dmesg.boot
> root on wd0a dumps on wd0b
>
> so you would
>
> /sbin/swapctl -d /dev/wd0b
> /sbin/savecore  -c
> /sbin/swapctl -a /dev/wd0b
>
> in this case...
>
> If the message reappears when rebooting after that, your kernel had
> crashed again, instead of shutting down cleanly.
>
> Good luck!
>
>         -is