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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
       enable it.

       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
       that directory.

       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)