Savecore

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Solaris SysAdmin commands


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 can be configured by dumpadm(1M) to save crash dump
     data  in either a compressed or uncompressed format. For the
     compressed format, savecore saves the crash dump data in the
     file  directory/vmcore.N.z,  where  N  in  the  pathname  is
     replaced by a number  which  increments  by  one  each  time
     savecore  is  run  in  directory. The compressed file can be
     uncompressed in  a  separate  step  using  the  -f  dumpfile
     option.  For  the  uncompressed  format,  savecore saves the
     crash dump data  in  the  file  directory/vmcore.N  and  the
     kernel's namelist in directory/unix.N.

     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  con-
     taining  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 facil-
     ity  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
                    device.  When   given   directory/vmcore.N.z,
                    uncompress  the  file to vmcore.N and unix.N,
                    where  N  is  the  same  number  as  in   the
                    compressed name.

                    This option may also be useful if the  infor-
                    mation  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 alter-
                    ing the system in any way. This option forces
                    savecore  to save a live snapshot of the sys-
                    tem 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 performed if you have configured your sys-
                    tem  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
         o    directory/vmcore.N

         o    directory/unix.N

         o    directory/bounds

         o    directory/minfree

         o    /var/crash/`uname -n` (default  crash  dump  direc-
              tory)

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcs                      |
    |_____________________________|_____________________________|

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 service'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.


--Tom Stevenson 13:50, 26 April 2012 (EDT)

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