Operating DAT

1. Take a snapshot dump of the system that failed, using the DUMP utility. Refer to System Startup, Configuration, and Shutdown Reference Manual for information about making a DUMP tape.

2. Invoke the DAT utility; the command interpreter prompt (usually a colon) is replaced by the DAT program prompt:

   
      :DAT
      $nmdat>
   
      OR:
   
      :RUN DAT.DAT.TELESUP
      $nmdat>
   
   

3. Create the dump. A request will appear on the system console to mount the dump tape. The following example creates the dump EXAMP.

   
      $nmdat>GETDUMP examp
   
      Please mount dump volume #1.
   
   

4. Mount the dump tape when prompted by the message on the system console. Press RETURN. As the dump is being loaded, DAT will display a series of messages about the dump indicating GETDUMP progress:

   
    Tape created by SOFTDUMP 99999X A.00.00
    MPE-XL B.05.09 dumped on SAT, OCT 20, 1990,  1:44 AM
   
         Dump Tape Contents
         ------------------
   
       PIM00       4.0 Kbytes
       MEMDUMP    32.0 Mbytes
       VM001      59.5 Mbytes
   
    This dump will require approximately 32.1 Mbytes
    (#131387 sectors) of disc space.
   
    Please stand by for disc space allocation.
   
                                 0        100%
    Loading tape file PIM00   :  +....+....+
    Loading tape file MEMDUMP :  +....+....+
    Loading tape file VM001   :  +....+....+
   
    Please stand by while dump pages are posted to disk.
   
    Dump disc file space reduced by 59% due to LZ data compression.
    $nmdat>
   
   

5. Open the dump. The following example opens the dump EXAMP.

   
      $nmdat>OPENDUMP examp
   
      Dump Title: System failure during performance testing.
      Last PIN  : 7  On ICS stack -- Dispatcher running
   
      $nmdat>
   
   

6. Analyze the dump, using the commands and DAT macros described later in this chapter. If the dump file set was opened successfully, you can display the machine registers, any data locations (using physical, secondary and virtual addressing modes), and the basic tables used in the virtual address translation process.

7. When finished with a dump file set, you can exit the utility or open another file set. All dump file sets remain in the system until you explicitly purge them with the PURGEDUMP command.

   
      $nmdat> PURGEDUMP examp
      $nmdat> EXIT
      :
   
   

NOTE: When you use the EXIT command in DAT, the DAT program terminates immediately.

Using the info= String

   run dat; info='{cmd1, cmd2, cmd3}'

Automatic DATINIT Files

1. 
      run dat; info="{cmdlist}"  INFO string command list
   
   

2. 
      DATINIT.ProgGrp.ProgAcnt   program file group/account
   
   

3. 
      DATINIT.UserGrp.UserAcnt   user's group/account
   
   

    run dat;info="use close; use close"

Operating Restrictions

• The only symbols that are accessible in CM are the SL.PUB.SYS symbols. This is because SL.PUB.SYS is the only CM library/program file that is dumped by the DUMP utility.

• Typically, only NL.PUB.SYS symbols are accessible in NM. This is because NL.PUB.SYS is treated as a special file by the DUMP utility. The complete NL is dumped along with a pre-built symbol table which enables DAT to quickly map back and forth between addresses and symbol names. Additional executable libraries may also be accessible, if they have been marked to be dumped.

• NM stack traces will only trace procedures in NL.PUB.SYS. An exception to this is when the unwind descriptors for the code which called NL.PUB.SYS are memory-resident.

• For the standard functions nmaddr and nmfile, only addresses contained in the system library are valid.

• You cannot use the following DEBUG commands in DAT:

CLOSEDUMP

closes a dump file set

DEBUG

gives access to restricted debugging mode

DPIB

displays data from PIB for a block

DPTREE

prints the process tree

DUMPINFO

displays dump file set information

GETDUMP

reads in dump tape, creates dump file set

INITxx

initializes DAT registers from specified location

OPENDUMP

opens a dump file set

PURGEDUMP

deletes a dump file set