xref: /freebsd/sbin/savecore/savecore.8 (revision 1fa8142d)

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.\"     From: @(#)savecore.8	8.1 (Berkeley) 6/5/93
.\" $FreeBSD$
.\"
.Dd September 23, 1994
.Dt SAVECORE 8
.Os
.Sh NAME
.Nm savecore
.Nd "save a core dump of the operating system"
.Sh SYNOPSIS
.Nm
.Fl c
.Nm
.Op Fl fkvz
.Op Ar directory Op Ar device ...
.Sh DESCRIPTION
The
.Nm
utility
copies a core dump into
.Ar directory ,
or the current working directory if no
.Ar directory
argument is given,
and enters a reboot message and information about the core dump into
the system log.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl c
Clear the dump, so that future invocations of
.Nm
will ignore it.
.It Fl f
Force a dump to be taken even if the dump was cleared.
.It Fl k
Do not clear the dump after saving it.
.It Fl v
Print out some additional debugging information.
.It Fl z
Compress the core dump and kernel (see
.Xr gzip 1 ) .
.El
.Pp
The
.Nm
utility
looks for dumps on each device specified by the
.Ar device
argument(s), or on each device in
.Pa /etc/fstab
marked as
.Dq dump
or
.Dq swap .
The
.Nm
utility
checks the core dump in various ways to make sure that it is complete.
If it passes these checks, it saves the core image in
.Ar directory Ns Pa /vmcore.#
and information about the core in
.Ar directory Ns Pa /info.#
The ``#'' 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
The
.Nm
utility
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
The
.Nm
utility
is meant to be called near the end of the initialization file
.Pa /etc/rc
(see
.Xr rc 8 ) .
.Sh BUGS
The minfree code does not consider the effect of compression or sparse files.
.Sh SEE ALSO
.Xr gzip 1 ,
.Xr getbootfile 3 ,
.Xr dumpon 8 ,
.Xr syslogd 8
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.1 .