SAVECORE(8) System Manager's Manual SAVECORE(8)NAME
savecore - save a core dump of the operating system
SYNOPSIS
savecore dirname [ system ]
DESCRIPTION
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.
It saves the core image in the file dirname/core.n and its corresponding namelist in 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 savecore is run in that directory.
Before savecore writes out a core image, it reads a number from the file dirname/minfree. If there are fewer free blocks on the file sys-
tem which contains 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).
Savecore also writes a reboot message in the shut down log. If the system crashed as a result of a panic, savecore records the panic
string in the shut down log too.
If 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.
FILES
/usr/adm/shutdownlogshutdown log
/unix current UNIX
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 init by the system; however, this is difficult because the system may have to be rebooted a second
time if the root filesystem is patched.
3rd Berkeley DistributionSAVECORE(8)
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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 5.10 25 Sep 2004 savecore(1M)