Obtaining address space and data space identifiers

You will need to dump the following areas to get complete z/OS® UNIX data in a dump:
  • The kernel address space
  • The kernel data space for kernel data
  • Any other kernel data spaces that may be associated with the problem
  • Any colony address spaces and associated data spaces that may be associated with the problem.
  • Any process address spaces that may be associated with the problem
  • Appropriate storage data areas containing system control blocks and other information
Use the following DISPLAY commands to find the correct areas to dump:
  • Display system activity to find the kernel address space and its associated data spaces. 
    D A,OMVS

    The display output shows the kernel address space identifier (ASID) as A=nnnn, where nnnn is the hexadecimal ASID value.

    The display output shows the data space names that are associated with the kernel address space as DSPNAME=BPX..... or DSPNAME=SYS...... The system uses these data spaces as follows:
    • BPXSMBITS—for shared memory, memory map, and large message queue buffers. BPXSMBITS should be dumped when you dump BPXD data spaces for these components.
    • BPXDQxxx—for message queues (where xxx can be the number 1 through 9)
    • BPXDSxxx—for shared memory
    • BPXDOxxx—for Outboard Communications Server (OCS)
    • BPXDMxxx—for memory map
    • BPXFSCDS—for couple data set (CDS)
    • SYSZBPX1—for kernel data (including CTRACE buffers)
    • SYSZBPX2—for file system data
    • SYSZBPX3—for pipes
    • SYSIGWB1—for byte-range locking
    • SYSGFU01—for DFSMS file system
    • SYSZBPXC—for Converged INET sockets
    • SYSZBPXL—for local INET sockets
    • SYSZBPXU—for AF_UNIX sockets

    The kernel data space, SYSZBPX1, is always needed. You should dump other data spaces if there is reason to believe that they contain data that could be useful in analyzing the problem.

  • To display system activity to find the colony address spaces and their associated data spaces, use: 
    D A,name

    The name is the name that is specified in the ASNAME parameter of the FILESYSTYPE statement in BPXPRMxx.

    The display output shows the colony address space identifier (ASID) as A=nnnn, where nnnn is the hexadecimal ASID value.

    The display output shows the data space names that are associated with the colony address space as DSPNAME=SYS......

  • To display status to see the process information for address spaces or file system information. 
    D OMVS,A=ALL

    The display output shows all of the active processes, their ASIDs, process IDs, parent process IDs, and states. Use this information to find the ASIDs for the processes to be included in the dump request.

  • To display global resource serialization information to see possible latch contention. 
    D GRS,C

    This display may show latch contention, which could be the cause of the problem. You should dump the address space of the process holding the latch. If the latch is a file system latch, dump the file system data space SYSZBPX2 also. You may want to repeat the command several times to see if any contention shown in one display is relieved.

  • To display all open files in the system to determine what address spaces to include in the dump.
    zlsof

    The display output shows all open files, the associated command, process ID, user ID, and file system name for each open file. You can then use the D OMVS,U= and D OMVS,PID= commands. zlsof is a z/OS UNIX System Services REXX exec that can be executed as a shell command (/bin/zlsof), TSO/E REXX exec , or System REXX exec.

Parent topic: Getting the right z/OS UNIX data in a dump