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savecore(8) [freebsd man page]

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

NAME
savecore -- save a core dump of the operating system SYNOPSIS
savecore -c [-v] [device ...] savecore -C [-v] [device ...] savecore [-fkvz] [-m maxdumps] [directory [device ...]] DESCRIPTION
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: -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. -m maxdumps Maximum number of dumps to store. Once the number of stored dumps is equal to maxdumps the counter will restart from 0. -v Print out some additional debugging information. Specify twice for more information. -z Compress the core dump and kernel (see gzip(1)). 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.#. 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 successfully runs. The savecore utility also checks the available disk space before attempting 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 after 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 initialization file /etc/rc (see rc(8)). SEE ALSO
gzip(1), getbootfile(3), textdump(4), tar(5), dumpon(8), syslogd(8) HISTORY
The savecore utility appeared in 4.1BSD. Support for kernel textdumps appeared in FreeBSD 7.1. BUGS
The minfree code does not consider the effect of compression or sparse files. BSD
December 17, 2012 BSD

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savecore(1M)						  System Administration Commands					      savecore(1M)

NAME
savecore - save a crash dump of the operating system SYNOPSIS
/usr/bin/savecore [-Lvd] [-f dumpfile] [directory] DESCRIPTION
The savecore utility saves a crash dump of the kernel (assuming that one was made) and writes a reboot message in the shutdown log. It is invoked by the dumpadm service each time the system boots. savecore saves the crash dump data in the file directory/vmcore.n and the kernel's namelist in directory/unix.n. The trailing .n in the pathnames is replaced by a number which grows every time savecore is run in that directory. Before writing out a crash dump, savecore reads a number from the file directory/minfree. This is the minimum number of kilobytes that must remain free on the file system containing directory. If after saving the crash dump the file system containing directory would have less free space the number of kilobytes specified in minfree, the crash dump is not saved. if the minfree file does not exist, savecore assumes a minfree value of 1 megabyte. The savecore utility also logs a reboot message using facility LOG_AUTH (see syslog(3C)). If the system crashed as a result of a panic, savecore logs the panic string too. OPTIONS
The following options are supported: -d Disregard dump header valid flag. Force savecore to attempt to save a crash dump even if the header information stored on the dump device indicates the dump has already been saved. -f dumpfile Attempt to save a crash dump from the specified file instead of from the system's current dump device. This option may be useful if the information stored on the dump device has been copied to an on-disk file by means of the dd(1M) command. -L Save a crash dump of the live running Solaris system, without actually rebooting or altering the system in any way. This option forces savecore to save a live snapshot of the system to the dump device, and then immediately to retrieve the data and to write it out to a new set of crash dump files in the specified directory. Live system crash dumps can only be per- formed if you have configured your system to have a dedicated dump device using dumpadm(1M). savecore -L does not suspend the system, so the contents of memory continue to change while the dump is saved. This means that live crash dumps are not fully self-consistent. -v Verbose. Enables verbose error messages from savecore. OPERANDS
The following operands are supported: directory Save the crash dump files to the specified directory. If directory is not specified, savecore saves the crash dump files to the default savecore directory, configured by dumpadm(1M). FILES
directory/vmcore.n directory/unix.n directory/bounds directory/minfree /var/crash/'uname -n' default crash dump directory ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ SEE ALSO
adb(1), mdb(1), svcs(1), dd(1M), dumpadm(1M), svcadm(1M), syslog(3C), attributes(5), smf(5) NOTES
The system crash dump service is managed by the service management facility, smf(5), under the service identifier: svc:/system/dumpadm:default Administrative actions on this service, such as enabling, disabling, or requesting restart, can be performed using svcadm(1M). The ser- vice's status can be queried using the svcs(1) command. If the dump device is also being used as a swap device, you must run savecore very soon after booting, before the swap space containing the crash dump is overwritten by programs currently running. SunOS 5.11 25 Sep 2004 savecore(1M)

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