Date: Fri, 6 Apr 2012 13:13:05 -0700 From: Devin Teske <devin.teske@fisglobal.com> To: "'gahn'" <ipfreak@yahoo.com>, "'freebsd general questions'" <freebsd-questions@freebsd.org> Subject: RE: learning freebsd kernel Message-ID: <08eb01cd1431$adfc5280$09f4f780$@fisglobal.com> In-Reply-To: <1333742522.34885.YahooMailNeo@web130202.mail.mud.yahoo.com> References: <1333735492.43069.YahooMailNeo@web130205.mail.mud.yahoo.com> <08b701cd1420$f4e21a60$dea64f20$@fisglobal.com> <1333742522.34885.YahooMailNeo@web130202.mail.mud.yahoo.com>
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> -----Original Message-----
> From: gahn [mailto:ipfreak@yahoo.com]
> Sent: Friday, April 06, 2012 1:02 PM
> To: Devin Teske; 'freebsd general questions'
> Subject: Re: learning freebsd kernel
>=20
> thanks devin for the great tip. yeah, now i got core dumps...:)
>=20
> but where is my "gdb" under that "debug.kdb.available"?
>=20
I'm not sure I understand the question.
debug.kdb.available shows "ddb" for me
I usually use kgdb(1) for examining kernel core files.
--=20
Devin
> best
>=20
> /gahn
>=20
>=20
>=20
> ----- Original Message -----
> From: Devin Teske <devin.teske@fisglobal.com>
> To: 'gahn' <ipfreak@yahoo.com>; 'freebsd general questions' <freebsd-
> questions@freebsd.org>
> Cc:
> Sent: Friday, April 6, 2012 2:13 PM
> Subject: RE: learning freebsd kernel
>=20
>=20
>=20
> > -----Original Message-----
> > From: owner-freebsd-questions@freebsd.org [mailto:owner-freebsd-
> > questions@freebsd.org] On Behalf Of gahn
> > Sent: Friday, April 06, 2012 11:05 AM
> > To: freebsd general questions
> > Subject: learning freebsd kernel
> >
> > hi gurus:
> >
> > how could i create the core dumps on freebsd kernel? i am trying to cre=
ate a
> > kernel core dump on 8.1 but it didn't happen:
> >
> > # sysctl -w debug.kdb.panic=3D1
> >
> > well the system went panic, entered the mode db>. i did "reboot' but th=
ere
> was
> > no core/kernel dumps under /var/crash.
> >
>=20
> Did you set the "dumpdev" directive in /etc/rc.conf?
>=20
> % grep dumpdev /etc/defaults/rc.conf
> dumpdev=3D"NO"=A0 =A0 =A0 =A0 =A0 =A0 # Device name to crashdump to (or N=
O).
> savecore_flags=3D""=A0 =A0 =A0 # Used if dumpdev is enabled above, and p=
resent.
>=20
> You should set the value of dumpdev to your swap device.
>=20
> You can get this value by executing the following:
>=20
> awk '$3~/swap/{print $1}' /etc/fstab
>=20
> Should produce something like "/dev/mfid0s1b" or "da0s1b" or "ada0s1b" or
> "ad0s1b" etc. depending on your RELEASE and hardware.
>=20
> If the output is, for example, "/dev/mfid0s1b", you should add the follow=
ing
to
> /etc/rc.conf:
>=20
> dumpdev=3D"/dev/mfid0s1b"
>=20
> --
> Devin
>=20
>=20
> > the customized kernel has those information enabled:
> >
> > # Debugging for use in -current
> > options=A0=A0=A0=A0=A0=A0=A0=A0 KDB=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0 # Enable kernel debugger support.
> > options=A0=A0=A0=A0=A0=A0=A0=A0 DDB=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0 # Support DDB.
> > options=A0=A0=A0=A0=A0=A0=A0=A0 GDB=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0 # Support remote GDB.
> >
> > user@host:~:$ sysctl -a | grep debug.kdb
> > debug.kdb.stop_cpus: 1
> > debug.kdb.trap_code: 0
> > debug.kdb.trap: 0
> > debug.kdb.panic: 0
> > debug.kdb.enter: 0
> > debug.kdb.current: ddb
> > debug.kdb.available: ddb
> >
> >
> >
> > by the way, where is my gdb? on one of my company's machisne, it looks =
like
> > this:
> >
> > debug.kdb.available: ddb gdb
> >
> > thank you all
> >
> > /gahn
> > _______________________________________________
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> > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> > To unsubscribe, send any mail to "freebsd-questions-
> unsubscribe@freebsd.org"
>=20
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