Net2/usr/src/sbin/savecore/savecore.8

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.\"     @(#)savecore.8	6.6 (Berkeley) 3/16/91
.\"
.Dd March 16, 1991
.Dt SAVECORE 8
.Os BSD 4
.Sh NAME
.Nm savecore
.Nd "save a core dump of the operating system"
.Sh SYNOPSIS
.Nm savecore
.Ar dirname
.Op Ar system
.Sh DESCRIPTION
.Nm Savecore
is meant to be called near the end of the initialization file
.Pa /etc/rc
(see
.Xr rc 8 ) .
Its function
is to save the core dump of the system (assuming one was made) and to
write a reboot message in the shutdown log.
.Pp
Operands supported by
.Nm savecore :
.Bl -tag -width Ar
.It Ar dirname
The directory name where the core dump will be written.
.It Ar system
If the core dump was from a system other than
.Pa /vmunix ,
the name
of that system must be supplied as
.Ar system .
.El
.Pp
.Nm Savecore
checks the core dump to be certain it corresponds with the
current running unix.  If the core dump is current, it saves the core
image in
.Ar dirname Ns Pa /vmcore.n
and the namelist
in
.Ar dirname Ns Pa /vmunix.n
Sequence numbers are incremented and appended to the end of the pathnames
each time
.Nm savecore
is run in the directory.
.Pp
Before savecore writes out a core image, it reads a number from the file
.Ar dirname Ns Pa /minfree .
If the number of free kilobytes on the filesystem which contains
.Ar dirname
is less than the number obtained from the minfree file,
the core dump is not saved.
If the minfree file does not exist, savecore always writes out the core
file (assuming that a core dump was taken).
.Pp
.Nm Savecore
also logs a reboot message using facility
.Dv LOG_AUTH
(see
.Xr syslog 3 )
If the system crashed as a result of a panic,
.Nm savecore
logs the panic string too.
.Sh FILES
.Bl -tag -width /vmunixxx -compact
.It Pa /vmunix
current
.Tn UNIX
.El
.Sh BUGS
Can be fooled into thinking a core dump is the wrong size.
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.1 .