Library /sys$common/syshlp/sda.hlb Operation  *Conan The Librarian (sorry for the slow response - running on an old VAX)

     You execute the System Dump Analyzer program by means of commands.
     SDA reads these commands from SYS$INPUT, which can be your terminal
     or a command file.  You can send the output to a file or to your
     terminal.

     Any of the following commands will invoke SDA:

 	$ ANALYZE/CRASH_DUMP dump_file
 	$ ANALYZE/SYSTEM
 	$ RUN SYS$SYSTEM:SDA

     When a fatal BUGCHECK error causes the system to crash, the system
     writes the current state of the hardware registers and all physical
     memory to a contiguous file called SYSDUMP.DMP in the SYSEXE account
     on the system disk.  Alternatively, the system's paging file may be
     specified as the destination of the dump information instead of
     SYSDUMP.DMP. This is useful on systems that have constrained disk space.

     Note that pages currently in the paging file (paged out) are not saved
     because the paging file is too large.  Although these pages are lost
     from the crash dump, the effect on debugging will be minimal because
     most pages relating to the crash are still in physical memory when
     the crash occurs, and are thus saved in the dump file.  Of course, if
     the paging file is used as a dump file, the pages that are there are
     wiped out.

     It is recommended that the system manager set up the system-startup file
     so that SDA is always run during system startup.  When executed at this
     time, SDA first checks to see if the system has just crashed.  If so,
     SDA executes the SDA commands in the system's startup-command file.
     If the system has not just crashed, SDA exits.

     The following example shows the SDA commands typically included in the
     system's startup file.  The most important of these is the COPY
     command, which copies the dump file to another file.  This operation
     is recommended because the system always overwrites this file in the event
     of a crash, and the record of the previous crash is lost unless another
     copy exists.  Furthermore, if the paging file was used as the dump file,
     the pages that contain the dump information are not available for paging
     until they are explicitly released by the COPY command.

 	$ !
 	$ !  Invoke the System Dump Analyzer if the system just crashed
 	$ !
 	$ ANALYZE/CRASH_DUMP SYS$SYSTEM:SYSDUMP
 	SET OUTPUT LPA0:SYSDUMP.LIS	! Make listing file
 	SHOW CRASH			! Display crash information
 	SHOW STACK			! Show current operating stack
 	SHOW SUMMARY			! List all active processes
 	SHOW PROCESS/PCB/PHD/REGISTERS	! Display current process
 	SHOW SYMBOLS/ALL		! Print the system symbol table
 	COPY SYS$SYSTEM:SAVEDUMP.DMP	! Save dump file for later
 	EXIT

     If you need more information on the crash, you can execute SDA
     interactively or add SDA commands to the startup file.