2.11BSD/src/sbin/savecore/savecore.8

.TH SAVECORE 8
.UC
.SH NAME
savecore \- save a core dump of the operating system
.SH SYNOPSIS
.B savecore
.I dirname
[
.I system
]
.SH DESCRIPTION
.PP
.I Savecore
is meant to be called at the end of the /etc/rc file.  Its function
is to save the core dump of the system (if one was made) and to
write a reboot message in the shutdown log.
.PP
It saves the core image in the file
.IR dirname /core.n
and its corresponding namelist in
.IR dirname /unix.n.
The second argument is the namelist for the system
which made the core image;
the current system is always assumed to be /unix.
The trailing ".n" in the pathnames is replaced by a number which grows
every time
.I savecore
is run in that directory.
.PP
Before savecore writes out a core image, it reads a number from the file
.IR dirname /minfree.
If there are fewer free blocks on the file system
which contains
.I dirname
than the number obtained from the minfree file, the core dump is not done.
If the minfree file does not exist, savecore always writes out the core
file (assuming that a core dump was taken).
.PP
.I Savecore
also writes a reboot message in the shut down log.  If the system crashed
as a result of a panic,
.I savecore
records the panic string in the shut down log too.
.PP
If
.I savecore
detects that the system time is wrong because of a crash
(the time in the core image is after the current time),
it will reset the system time to its best estimate of the time,
which is the time in the core image plus the elapsed time since the reboot.
It announces the time that it set when this occurs.
.SH FILES
.ta 2i
/usr/adm/shutdownlog	shutdown log
.br
/unix	current UNIX
.SH BUGS
The method used to determine whether a dump is present, and to prevent
the same core image from being saved multiple times,
is not elegant.
This information should be passed to \fIinit\fP by the system;
however, this is difficult because the system may have to be rebooted
a second time if the root filesystem is patched.