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SAVECORE(8)		FreeBSD	System Manager's Manual		   SAVECORE(8)

     savecore -- save a	core dump of the operating system

     savecore -c [-v] [device ...]
     savecore -C [-v] [device ...]
     savecore -L [-fvZz] [-m maxdumps] [directory]
     savecore [--libxo]	[-fkuvz] [-m maxdumps] [directory [device ...]]

     The savecore utility copies a core	dump into directory, or	the current
     working directory if no directory argument	is given, and enters a reboot
     message and information about the core dump into the system log.

     The options are as	follows:

     --libxo	  Generate output via libxo(3) in a selection of different hu-
		  man and machine readable formats.  See xo_parse_args(3) for
		  details on command line arguments.

     -C		  Check	to see if a dump exists, and display a brief message
		  to indicate the status.  An exit status of 0 indicates that
		  a dump is there, 1 indicates that none exists.  This option
		  is compatible	only with the [-v] option.

     -c		  Clear	the dump, so that future invocations of	savecore will
		  ignore it.

     -f		  Force	a dump to be taken even	if either the dump was cleared
		  or if	the dump header	information is inconsistent.

     -k		  Do not clear the dump	after saving it.

     -L		  Instruct savecore to generate	and save a kernel dump of the
		  running system, rather than copying one from a dump device.

     -m	maxdumps  Maximum number of dumps to store.  Once the number of	stored
		  dumps	is equal to maxdumps the counter will restart from 0.

     -u		  Uncompress the dump in case it was compressed	by the kernel.

     -v		  Print	out some additional debugging information.  Specify
		  twice	for more information.

     -Z		  Compress the dump (see zstd(1)).  This option	is only	sup-
		  ported in conjunction	with the -L option.  Regular dumps can
		  be configured	for compression	with zstd using	dumpon(8).

     -z		  Compress the dump (see gzip(1)).  The	dump may already be
		  compressed if	the kernel was configured to do	so by
		  dumpon(8).  In this case, the	option has no effect.

		  If used in conjunction with the -L option, the requested
		  live dump will be compressed with gzip.

     The savecore utility looks	for dumps on each device specified by the
     device argument(s), or on each device in /etc/fstab marked	as "dump" or
     "swap".  The savecore 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 directory/vmcore.# and information about the	core in
     directory/info.#.	If the core is encrypted, it saves the dump key	in
     directory/key.#.  The core	can be later decrypted using decryptcore(8).
     For kernel	textdumps generated with the textdump(4) facility, output will
     be	stored in the tar(5) format and	named directory/textdump.tar.#.	 The
     "#" is the	number from the	first line of the file directory/bounds, and
     it	is incremented and stored back into the	file each time savecore	suc-
     cessfully runs.

     The savecore utility also checks the available disk space before attempt-
     ing to make the copies.  If there is insufficient disk space in the file
     system containing directory, or if	the file directory/minfree exists and
     the number	of free	kilobytes (for non-superusers) in the file system af-
     ter the copies were made would be less than the number in the first line
     of	this file, the copies are not attempted.

     If	savecore successfully copies the kernel	and the	core dump, the core
     dump is cleared so	that future invocations	of savecore will ignore	it.

     The savecore utility is meant to be called	near the end of	the initial-
     ization file /etc/rc (see rc(8)).

     gzip(1), zstd(1), getbootfile(3), libxo(3), xo_parse_args(3), mem(4),
     textdump(4), tar(5), crashinfo(8),	decryptcore(8),	dumpon(8), syslogd(8)

     The savecore utility appeared in 4.1BSD.

     Support for kernel	textdumps appeared in FreeBSD 7.1.

     The minfree code does not consider	the effect of compression or sparse

FreeBSD	13.0			 April 4, 2022			  FreeBSD 13.0


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