Date: Fri, 6 Apr 2012 13:44:02 -0700 (PDT) From: gahn <ipfreak@yahoo.com> To: Devin Teske <devin.teske@fisglobal.com>, 'freebsd general questions' <freebsd-questions@freebsd.org> Subject: Re: learning freebsd kernel Message-ID: <1333745042.8621.YahooMailNeo@web130205.mail.mud.yahoo.com> In-Reply-To: <08eb01cd1431$adfc5280$09f4f780$@fisglobal.com> References: <1333735492.43069.YahooMailNeo@web130205.mail.mud.yahoo.com> <08b701cd1420$f4e21a60$dea64f20$@fisglobal.com> <1333742522.34885.YahooMailNeo@web130202.mail.mud.yahoo.com> <08eb01cd1431$adfc5280$09f4f780$@fisglobal.com>
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thanks devin:=0A=0Awhat i meant was that one of my company's servers looks =
like this:=0A=0Adebug.kdb.available: ddb gdb=0A=0A=0Ai am just wondering wh=
y that is...=0A=0Abest=0A=0A/gahn=0A=0A=0A=0A----- Original Message -----=
=0AFrom: Devin Teske <devin.teske@fisglobal.com>=0ATo: 'gahn' <ipfreak@yaho=
o.com>; 'freebsd general questions' <freebsd-questions@freebsd.org>=0ACc: =
=0ASent: Friday, April 6, 2012 4:13 PM=0ASubject: RE: learning freebsd kern=
el=0A=0A> -----Original Message-----=0A> From: gahn [mailto:ipfreak@yahoo.c=
om]=0A> Sent: Friday, April 06, 2012 1:02 PM=0A> To: Devin Teske; 'freebsd =
general questions'=0A> Subject: Re: learning freebsd kernel=0A> =0A> thanks=
devin for the great tip. yeah, now i got core dumps...:)=0A> =0A> but wher=
e is my "gdb" under that "debug.kdb.available"?=0A> =0A=0AI'm not sure I un=
derstand the question.=0A=0Adebug.kdb.available shows "ddb" for me=0A=0AI u=
sually use kgdb(1) for examining kernel core files.=0A-- =0ADevin=0A=0A=0A>=
best=0A> =0A> /gahn=0A> =0A> =0A> =0A> ----- Original Message -----=0A> Fr=
om: Devin Teske <devin.teske@fisglobal.com>=0A> To: 'gahn' <ipfreak@yahoo.c=
om>; 'freebsd general questions' <freebsd-=0A> questions@freebsd.org>=0A> C=
c:=0A> Sent: Friday, April 6, 2012 2:13 PM=0A> Subject: RE: learning freebs=
d kernel=0A> =0A> =0A> =0A> > -----Original Message-----=0A> > From: owner-=
freebsd-questions@freebsd.org [mailto:owner-freebsd-=0A> > questions@freebs=
d.org] On Behalf Of gahn=0A> > Sent: Friday, April 06, 2012 11:05 AM=0A> > =
To: freebsd general questions=0A> > Subject: learning freebsd kernel=0A> >=
=0A> > hi gurus:=0A> >=0A> > how could i create the core dumps on freebsd k=
ernel? i am trying to create a=0A> > kernel core dump on 8.1 but it didn't =
happen:=0A> >=0A> > # sysctl -w debug.kdb.panic=3D1=0A> >=0A> > well the sy=
stem went panic, entered the mode db>. i did "reboot' but there=0A> was=0A>=
> no core/kernel dumps under /var/crash.=0A> >=0A> =0A> Did you set the "d=
umpdev" directive in /etc/rc.conf?=0A> =0A> % grep dumpdev /etc/defaults/rc=
.conf=0A> dumpdev=3D"NO"=A0 =A0 =A0 =A0 =A0 =A0 # Device name to crashdump =
to (or NO).=0A> savecore_flags=3D""=A0 =A0 =A0=A0 # Used if dumpdev is enab=
led above, and present.=0A> =0A> You should set the value of dumpdev to you=
r swap device.=0A> =0A> You can get this value by executing the following:=
=0A> =0A> awk '$3~/swap/{print $1}' /etc/fstab=0A> =0A> Should produce some=
thing like "/dev/mfid0s1b" or "da0s1b" or "ada0s1b" or=0A> "ad0s1b" etc. de=
pending on your RELEASE and hardware.=0A> =0A> If the output is, for exampl=
e, "/dev/mfid0s1b", you should add the following=0Ato=0A> /etc/rc.conf:=0A>=
=0A> dumpdev=3D"/dev/mfid0s1b"=0A> =0A> --=0A> Devin=0A> =0A> =0A> > the c=
ustomized kernel has those information enabled:=0A> >=0A> > # Debugging for=
use in -current=0A> > options=A0=A0=A0=A0=A0=A0=A0=A0 KDB=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 # Enable kernel debugger supp=
ort.=0A> > options=A0=A0=A0=A0=A0=A0=A0=A0 DDB=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 # Support DDB.=0A> > options=A0=A0=A0=A0=
=A0=A0=A0=A0 GDB=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0 # Support remote GDB.=0A> >=0A> > user@host:~:$ sysctl -a | grep debug.=
kdb=0A> > debug.kdb.stop_cpus: 1=0A> > debug.kdb.trap_code: 0=0A> > debug.k=
db.trap: 0=0A> > debug.kdb.panic: 0=0A> > debug.kdb.enter: 0=0A> > debug.kd=
b.current: ddb=0A> > debug.kdb.available: ddb=0A> >=0A> >=0A> >=0A> > by th=
e way, where is my gdb? on one of my company's machisne, it looks like=0A> =
> this:=0A> >=0A> > debug.kdb.available: ddb gdb=0A> >=0A> > thank you all=
=0A> >=0A> > /gahn=0A> > _______________________________________________=0A=
> > freebsd-questions@freebsd.org mailing list=0A> > http://lists.freebsd.o=
rg/mailman/listinfo/freebsd-questions=0A> > To unsubscribe, send any mail t=
o "freebsd-questions-=0A> unsubscribe@freebsd.org"=0A> =0A> _____________=
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