SAVECORE(8) System Manager's Manual SAVECORE(8)
savecore - save a core dump of the operating system
/usr/etc/savecore [ -v ] directory [ system-name ]
savecore saves a core dump of the kernel (assuming that one was made)
and writes a reboot message in the shutdown log. It is meant to be
called near the end of the /etc/rc.local file after the system boots.
However, it is not normally run by default. You must edit that file to
savecore checks the core dump to be certain it corresponds with the
version of the operating system currently running. If it does,
savecore saves the core image in the file directory/vmcore.n and the
kernel's namelist in directory/vmunix.n. The trailing .n in the path-
names is replaced by a number which grows every time savecore is run in
Before savecore writes out a core image, it reads a number from the
file directory/minfree. This is the minimum number of kilobytes that
must remain free on the filesystem containing directory. If there is
less free space on the filesystem containing directory than the number
of kilobytes specified in minfree, 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).
savecore also logs a reboot message using facility LOG_AUTH (see sys-
log(3)). If the system crashed as a result of a panic, savecore logs
the panic string too.
If the core dump was from a system other than /vmunix, the name of that
system must be supplied as system-name.
-v Verbose. Enable verbose error messages from savecore.
/vmunix the kernel
syslog(3), panic(8S), sa(8)
savecore can be fooled into thinking a core dump is the wrong size.
You must run savecore very soon after booting -- before the swap space
containing the crash dump is overwritten by programs currently running.
Core images produced by SPARCstation1 systems, and from machines with
discontiguous physical memory, are sparse and contain holes. For exam-
ple, a core image of an 8 megabyte SPARCstation 1 might contain 3 to 4
megabytes of useful information, and thus only occupy 3 to 4 megabytes
of disk space, yet contain enough holes to appear to be 36 megabytes in
size. However, copying the core image will manifest the holes, so that
this copy will require 36 megabytes of disk space. If it is necessary
to move a core image, it is strongly recommended that the core image be
compressed with compress(1) before the transfer. The compressed image
may later be uncompressed on a system with sufficient disk space.
1 July 1990 SAVECORE(8)