HP OpenVMS Systems Documentation

OpenVMS VAX System Dump Analyzer Utility Manual

10.2 Examples of How to Cause System Failures

The following examples show the sequence of console commands needed to cause a system failure on each type of processor. In each instance, after halting the processor and examining its registers, you place the equivalent of --1 (for example, FFFFFFFF₁₆) into the PC. The value placed in the PSL sets the processor access mode to kernel and the IPL to 31. After these commands are executed, an INVEXCEPTN bugcheck is reported on the console terminal, followed by a listing of the contents of the processor registers.

The console volume of most processors contains a command file named either CRASH.COM or CRASH.CMD, which you can execute to perform these commands. Note that the console sessions recorded in this section omit much of the information the console displays in response to the listed commands.

VAX 85x0/8700/88x0

The following series of console commands causes a system failure on the VAX 85x0/8700/88x0 systems. (Note that the console prompt for the VAX 8810, 8820, and 8830 systems is PS-CIO-0> and not >>>.)

$ [Ctrl/P]
>>> SET CPU CURRENT_PRIMARY
>>> HALT
?00       Left CPU -- CPU halted
          PC = 8001911C
>>> @CRASH
!
! Command procedure to force bugcheck via access violation
!
SET VERIFY
SET CPU CURRENT_PRIMARY    !Select primary
EXAMINE PSL                !Display PSL
        M 00000000 00420008
EXAMINE/I/NEXT 4 0
.
.
.


DEPOSIT PC FFFFFFFF        !Set PC=-1 to force ACCVIO
DEPOSIT PSL 41F0000        !Set IPL=31, interrupt stack
CONTINUE                   !Execute from PC=-1

VAX 82x0/83x0, VAXstation 3520/3540, 6000 Series, and 9000 Series

The following console commands cause a system failure on a VAX 82x0/83x0 system, a VAXstation 3520/3540 system, a VAX 6000 series system, or a VAX 9000 series system.

$ [Ctrl/P]
        PC = 80008B1F
>>> E P
>>> E/I 0
>>> E/I +
>>> E/I +
>>> E/I +
>>> E/I +
>>> D/G F FFFFFFFF
>>> D P 41F0000
>>> C

VAX 8600/8650

The following console commands cause a system failure on the VAX 8600/8650 systems.

$ [Ctrl/P]
>>> @CRASH
    SET QUIET OFF          !Make clearer
    SET ABORT OFF          !Don't abort on E/VIR command
    HALT
        CPU stopped, INVOKED BY CONSOLE (CSM code 11)
        PC 80008B1F
    UNJAM                  !Clear the way
    E PSL                  !Display PSL
        U PSL 00000000
    E/I/N:4 0              !Display stack pointers
   .
   .
   .

    E SP                   !Get current stack pointers
        G 0E 80000C40
    E/vir/next:40 @        !Dump top of stack
   .
   .
   .

    D PC FFFFFFFF          !Invalidate the PC
    D PSL 1F0000           !Kernel mode, IPL 31
    SET ABORT ON           !Restore abort flag
    SET QUIET ON           !Shut output off
    CONTINUE               !Force a machine check

VAX-11/780 and VAX-11/785

The following console commands cause a system failure on the VAX-11/780 and VAX-11/785 processors.

$ [Ctrl/P]
>>> @CRASH
HALT                       !Halt system, examine PC,
HALTED AT 80008A89

EXAMINE PSL                !PSL,
00000000

EXAMINE/INTERN/NEXT:4 0    !and all stack pointers

DEPOSIT PC = -1            !Invalidate PC
DEPOSIT PSL = 41F0000       !Kernel mode, IPL 31

 CONTINUE

VAX-11/750

The following code causes a system failure on a VAX-11/750. On this processor, the HALT command is a NOP; a Ctrl/P automatically halts the processor.

$ [Ctrl/P]
>>> H
>>> E P
>>> E/I 0
>>> E/I +
>>> E/I +
>>> E/I +
>>> E/I +
>>> D/G F FFFFFFFF
>>> D P 41F0000
>>> C

MicroVAX 3400/3600/3900 Series, VAXstation/MicroVAX 3100, VAXstation/MicroVAX 2000, MicroVAX II, and VAX 4000 Series

To force a crash of a MicroVAX, you must first halt the processor. (After you halt the processor, press the HALT button again so that it is popped out and is not illuminated.) Then, issue the following console commands:

>>> E PSL
>>> E/I/N:4 0
>>> D PC FFFFFFFF
>>> D PSL 41F0000
>>> C

VAX-11/730

The following console commands cause a system failure on a VAX-11/730. Ctrl/P automatically halts the processor.

$ [Ctrl/P]
>>> H
>>> E PSL
>>> E/I/N:4 0
>>> D PC FFFFFFFF
>>> D PSL 1F0000
>>> C

SDA Usage Summary

The System Dump Analyzer is a utility that you can use to help determine the causes of system failures. This utility is also useful for examining the running system.

Format

analyze {/CRASH_DUMP [/RELEASE] filespec| /SYSTEM} [/SYMBOL=system-symbol-table]

Command Parameter

filespec
Name of the file that contains the dump you want to analyze. At least one field of the filespec is required, and it can be any field. The default filespec is the highest version of SYSDUMP.DMP in your default directory.

Usage Summary

The following table summarizes how to perform key SDA operations.

Operation	Command	Explanation or Requirements
Invoke SDA to analyze a system dump	$ ANALYZE/CRASH_DUMP filename	If you do not specify a file name, SDA prompts you for one. Reading the dump file usually requires system privilege (SYSPRV), but your system manager can allow less privileged processes to read dump files. Your process needs change-mode-to-kernel (CMKRNL) privilege to release page file dump blocks, whether you use the /RELEASE qualifier or the SDA COPY command.
Invoke SDA to analyze a running system	$ ANALYZE/SYSTEM	Your process must have change-mode-to-kernel (CMKRNL) privilege. You cannot specify a file name with the /SYSTEM qualifier.
Send all output from SDA to a file	SDA> SET OUTPUT filename	The file produced is 132 columns wide and is formatted for output to a printer.
Redirect the output to your terminal	$ SET OUTPUT SYS$OUTPUT
Send a copy of all the commands you enter and all the output those commands produce to a file	SDA> SET LOG filename	The file produced is 132 columns wide and is formatted for output to a printer.
Exit an SDA display or the SDA utility	SDA> EXIT	If SDA is in display mode, you must use the EXIT command twice: once to exit display mode and a second time to exit SDA.

SDA Qualifiers

The following qualifiers, described in this section, determine whether the object of an SDA session is a crash dump or a running system. They also help create the environment of an SDA session. Table SDA-10 briefly describes the SDA qualifiers.

**Table SDA-10 Descriptions of SDA Qualifiers**
Qualifier	Description
/CRASH_DUMP	Invokes SDA to analyze a specified dump file
/RELEASE	Invokes SDA to release those blocks that are occupied by a crash dump in a specified system paging file
/SYMBOL	Specifies a system symbol table for SDA to use in place of the system symbol table it uses by default (SYS$SYSTEM:SYS.STB)
/SYSTEM	Invokes SDA to analyze a running system

/CRASH_DUMP

Invokes SDA to analyze the specified dump file.

Format

/CRASH_DUMP filespec

Parameter

filespec
Name of the crash dump file to be analyzed. The default file specification is:
SYS$DISK:[default-dir]SYSDUMP.DMP
SYS$DISK and [default-dir] represent the disk and directory specified in your last SET DEFAULT command. If you do not specify filespec, SDA prompts you for it.

Description

See Section 2 for additional information on crash dump analysis.

Examples

#1
$ ANALYZE/CRASH_DUMP SYS$SYSTEM:SYSDUMP.DMP $ ANALYZE/CRASH SYS$SYSTEM

These commands invoke SDA to analyze the crash dump stored in SYS$SYSTEM:SYSDUMP.DMP.

#2
$ ANALYZE/CRASH SYS$SYSTEM:PAGEFILE.SYS

This command invokes SDA to analyze a crash dump stored in the system paging file.

/RELEASE

Invokes SDA to release those blocks in the specified system paging file occupied by a crash dump.

Format

/RELEASE filespec

Parameter

filespec
Name of the system page file (SYS$SYSTEM:PAGEFILE.SYS). The default file specification is:
SYS$DISK:[default-dir]SYSDUMP.DMP
SYS$DISK and [default-dir] represent the disk and directory specified in your last SET DEFAULT command. If you do not specify filespec, SDA prompts you for it.

Description

You use the /RELEASE qualifier to release from the system paging file those blocks occupied by a crash dump. When invoked with the /RELEASE qualifier, SDA immediately deletes the dump from the paging file and allows no opportunity to analyze its contents.
When you specify the /RELEASE qualifier in the ANALYZE command, you must also do the following:

Use the /CRASH_DUMP qualifier.
Include the name of the system paging file (SYS$SYSTEM:PAGEFILE.SYS) as the filespec.

If you do not specify the system paging file or the specified paging file does not contain a dump, SDA generates the following messages:
%SDA-E-BLKSNRLSD, no dump blocks in page file to release, or not page file %SDA-E-NOTPAGFIL, specified file is not the page file

Example


$ ANALYZE/CRASH_DUMP/RELEASE SYS$SYSTEM:PAGEFILE.SYS

This command invokes SDA to release to the paging file those blocks in SYS$SYSTEM:PAGEFILE.SYS occupied by a crash dump.

/SYMBOL

Specifies a system symbol table for SDA to use in place of the system symbol table it uses by default (SYS$SYSTEM:SYS.STB).

Format

/SYMBOL =system-symbol-table

Parameter

system-symbol table
File specification of the SDA system symbol table needed to define symbols required by SDA to analyze a dump from a particular system. The specified system-symbol-table must contain those symbols required by SDA to find certain locations in the executive image.
If you do not specify the /SYMBOL qualifier, SDA uses SYS$SYSTEM:SYS.STB by default. When you do specify the /SYMBOL qualifier, SDA assumes the default disk and directory to be SYS$DISK: that is, the disk and directory specified in your last SET DEFAULT command. If SDA is given a file that is not a system symbol table in the /SYMBOL qualifier, it halts with a fatal error.

Description

The /SYMBOL qualifier allows you to specify a system symbol table, other than SYS$SYSTEM:SYS.STB, to load into the SDA symbol table. This might be necessary, for instance, to analyze a crash dump taken on a processor running a different version of OpenVMS.
You can use the /SYMBOL qualifier whether you are analyzing a system dump or a running system.

Example


$ ANALYZE/CRASH_DUMP/SYMBOL=SYS$CRASH:SYS.STB SYS$SYSTEM

This command invokes SDA to analyze the crash dump stored in SYS$SYSTEM:SYSDUMP.DMP, using the system symbol table at SYS$CRASH:SYS.STB.

/SYSTEM

Invokes SDA to analyze a running system.

Format

/SYSTEM

Parameters

None.

Description

See Section 3 for a full discussion of using SDA to analyze a running system.
You cannot specify the /CRASH_DUMP or /RELEASE qualifiers when you include the /SYSTEM qualifier in the ANALYZE command.

Example


$ ANALYZE/SYSTEM

This command invokes SDA to analyze the running system.

SDA Commands

Table SDA-11 briefly describes the SDA commands that are explained fully in the following section.

**Table SDA-11 Descriptions of SDA Commands**
Command	Description
@ (Execute Procedure)	Causes SDA to execute SDA commands contained in a file
ATTACH	Switches control of your terminal from your current process to another process in your job
COPY	Copies the contents of the dump file to another file
DEFINE	Assigns a value to a symbol or associates an SDA command with a terminal key
EVALUATE	Computes and displays the value of the specified expression in both hexadecimal and decimal
EXAMINE	Displays either the contents of a location or range of locations in physical memory, or the contents of a register
EXIT	Exits from an SDA display or exits from the SDA utility
FORMAT	Displays a formatted list of the contents of a block of memory
HELP	Displays information about the SDA utility, its operation, and the format of its commands
READ	Loads the global symbols contained in the specified object module into the SDA symbol table
REPEAT	Repeats execution of the last command issued
SEARCH	Scans a range of memory locations for all occurrences of a specified value
SET CPU	Selects a processor to become the SDA current CPU
SET LOG	Initiates or discontinues the recording of an SDA session in a text file
SET OUTPUT	Redirects output from SDA to the specified file or device
SET PROCESS	Selects a process to become the SDA current process
SET RMS	Changes the options shown by the SHOW PROCESS/RMS command
SHOW CALL_FRAME	Displays the locations and contents of the longwords representing a procedure call frame
SHOW CLUSTER	Displays connection manager and system communications services (SCS) information for all nodes in a cluster
SHOW CONNECTIONS	Displays information about all active connections between SCS processes or a single connection
SHOW CPU	Displays information about the state of a processor at the time of the system failure
SHOW CRASH	In the analysis of a system failure, displays information about the state of the system at the time of the failure; in the analysis of a running system, provides information identifying the system
SHOW DEVICE	Displays a list of all devices in the system and their associated data structures or displays the data structures associated with a given device or devices
SHOW EXECUTIVE	Displays the location and size of each loadable image that makes up the executive
SHOW HEADER	Displays the header of the dump file
SHOW LAN	Displays information contained in various local area network (LAN) data structures
SHOW LOCK	Displays information about all lock management locks in the system, cached locks, or a specified lock
SHOW LOGS	Displays information about transaction logs currently open for the node
SHOW PAGE_TABLE	Displays a range of system page table entries, the entire system page table, or the entire global page table
SHOW PFN_DATA	Displays information that is contained in the page lists and PFN database
SHOW POOL	Displays information about the disposition of paged and nonpaged memory, nonpaged dynamic storage pool, and paged dynamic storage pool
SHOW PORTS	Displays those portions of the port descriptor table (PDT) that are port independent
SHOW PROCESS	Displays the software and hardware context of any process in the balance set
SHOW RESOURCE	Displays information about all resources in the system or about a resource associated with a specific lock
SHOW RMS	Displays the RMS data structures selected by the SET RMS command to be included in the default display of the SHOW PROCESS/RMS command
SHOW RSPID	Displays information about response IDs (RSPIDs) of all SCS connections or, optionally, a specific SCS connection
SHOW SPINLOCKS	Displays information taken from the data structures that provide system synchronization in a multiprocessing environment
SHOW STACK	Displays the location and contents of the four process stacks (of the SDA current process) and the interrupt stack (of the SDA current CPU)
SHOW SUMMARY	Displays a list of all active processes and the values of the parameters used in swapping and scheduling those processes
SHOW SYMBOL	Displays the hexadecimal value of a symbol and, if the value is equal to an address location, the contents of that location
SHOW TRANSACTIONS	Displays information about all transactions on the node or about a specified transaction
SPAWN	Creates a subprocess of the process currently running SDA, copying the context of the current process to the subprocess
VALIDATE QUEUE	Validates the integrity of the specified queue by checking the pointers in the queue

Contents

Index