OpenBSD-4.6/sbin/savecore/savecore.8

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.\"	$OpenBSD: savecore.8,v 1.17 2008/09/10 22:17:33 sobrado Exp $
.\"	$NetBSD: savecore.8,v 1.11 1995/06/27 22:40:46 briggs Exp $
.\"
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.\"     @(#)savecore.8	8.1 (Berkeley) 6/5/93
.\"
.Dd $Mdocdate: September 10 2008 $
.Dt SAVECORE 8
.Os
.Sh NAME
.Nm savecore
.Nd "save a core dump of the operating system"
.Sh SYNOPSIS
.Nm savecore
.Op Fl cfvz
.Op Fl N Ar system
.Ar directory
.Sh DESCRIPTION
.Nm
copies the currently running kernel and its associated core dump into
.Fa directory ,
and enters a reboot message and information about the core dump into
the system log.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl c
Clears the dump, so that future invocations of
.Nm
will ignore it.
.It Fl f
Forces a dump to be taken even if the dump doesn't appear correct or there
is insufficient disk space.
.It Fl N Ar system
Use
.Ar system
as the kernel instead of the default
.Pa /bsd .
.It Fl v
Prints out some additional debugging information.
.It Fl z
Compresses the core dump and kernel (see
.Xr compress 1 ) .
.El
.Pp
.Nm
checks the core dump in various ways to make sure that it is current and
that it corresponds to the currently running system.
If it passes these checks, it saves the core image in
.Ar directory Ns Pa /bsd.#.core
and the system in
.Ar directory Ns Pa /bsd.#
(or in
.Ar directory Ns Pa /bsd.#.core.Z
and
.Ar directory Ns Pa /bsd.#.Z ,
respectively, if the
.Fl z
option is used).
The
.Dq #
is the number from the first line of the file
.Ar directory Ns Pa /bounds ,
and it is incremented and stored back into the file each time
.Nm
successfully runs.
.Pp
.Nm
also checks the available disk space before attempting to make the copies.
If there is insufficient disk space in the filesystem containing
.Ar directory ,
or if the file
.Ar directory Ns Pa /minfree
exists and the number of free kilobytes (for non-superusers) in the
filesystem after the copies were made would be less than the number
in the first line of this file, the copies are not attempted.
.Pp
If
.Nm
successfully copies the kernel and the core dump, the core dump is cleared
so that future invocations of
.Nm
will ignore it.
.Pp
.Nm
is meant to be called near the end of the initialization file
.Pa /etc/rc
(see
.Xr rc 8 ) .
.Sh FILES
.Bl -tag -width /bsdxx -compact
.It Pa /bsd
current kernel
.El
.Sh SEE ALSO
.Xr compress 1 ,
.Xr crash 8 ,
.Xr syslogd 8
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.1 .
.Sh BUGS
The minfree code does not consider the effect of compression.