VM65401: DESTRUCTIVE OVERLAP OCCURS DURING FORMSSI UPGRADE

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible in next release.

Error description

• If the Architecture Description Block (ARDBK) associated with a
  member in a z/VM Single System Image (SSI) cluster grows beyond
  the base 512 byte length, a FORMSSI UPGRADE is necessary to
  expand each member's ARDBK section in the Persistent Data Record
  (PDR)
  
  The FORMSSI command handler (HCPPDF) expands each system's
  section in the PDR through the use of a single MVCL instruction.
  In the problem scenario, the MVCL received condition code 3
  (destructive overlap) and the system information was not
  correctly expanded.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All z/VM Single System Image cluster users.  *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  When attempting to upgrade a z/VM Single System Image (SSI)
  cluster persistent data record (PDR), the FORMSSI utility
  UPGRADE function may not appropriately expand the system records
  If the Architecture Description Block (ARDBK) associated with a
  member in a z/VM SSI cluster grows beyond the length supported
  by the PDR on disk, a FORMSSI UPGRADE is necessary to expand
  each member's system section in the PDR.
  
  The FORMSSI command handler (HCPPDF) expands each system's
  section in the PDR through the use of a single MVCL
  instruction.  This attempts to move the data in the Persistent
  Data Record Block (PDRBK) to its new location within the same
  block.  In the problem scenario, the MVCL received condition
  code 3 (destructive overlap) and the system information was not
  correctly expanded.
  

Problem conclusion

Temporary fix

Comments

• The FORMSSI command handler (HCPPDF) has been updated to use a
  temporary buffer in order to move the system data within the
  persistent data record (PDR).  The data is moved from the
  Persistent Data Record Block (PDRBK) in memory to the temporary
  buffer and then moved from the temporary buffer to the new
  location in the PDRBK.  Since the moves occur between different
  buffers, the destructive overlay can no longer occur.
  
  The z/VM CP nucleus has been updated to automatically perform
  the FORMSSI UPGRADE function during IPL if the system determines
  that the system record length of the PDR on disk is smaller than
  the system record length of the PDR in the IPLing system.
  
  Entry point HCPPDRRD in HCPPDR has been updated to call a new
  entry point (HCPPDRUG) to expand the system records in the PDR
  to the length of the system record in use by the IPLing system.
  Before upgrading the PDR, the system issues the following new
  message:
  
     HCP1635I  Persistent data record (PDR) on volume <label> for
               SSI <ssi_name> will be automatically upgraded.
  
  If the upgrade is unsuccessful, the system will either issue
  hard abend ARD011 or issue the following new message and enter
  disabled wait state 9052:
  
     HCP9052W  Error upgrading PDR on volume <label> for SSI
               <ssi_name>
  
  The documentation changes associated with this APAR follow.
  
  ===============================================================
  
  The revised information that follows will be included in any
  future updates to the following publications:
  
  1. GC24-6177-04 z/VM: CP Messages and Codes version 6 release 3
  
     A. Add the following new message to the CP Messages section
        of Chapter 3 System Messages:
        __________________________________________________________
  
        HCP1635I  Persistent data record (PDR) on volume <label>
                  for SSI <ssi_name> will be automatically
                  upgraded.
  
        Explanation: This message is issued during system
        initialization to indicate that the system records in the
        persistent data record (PDR) associated with the IPLing
        system are larger than the records associated with the PDR
        for the specified z/VM Single System Image (SSI) cluster
        on the given volume.  The system records on disk must be
        expanded in order for the system to initialize and
        function in the SSI cluster.
  
        System Action: The system automatically upgrades the PDR
        on the specified volume and continues initialization.  If
        the upgrade is unsuccessful, the system will either issue
        hard abend ARD011 or will issue message HCP9052W and enter
        disabled wait state 9052.
  
        User Response: See the documentation for hard abend ARD011
        or message HCP9052W in z/VM: CP Messages and Codes in
        order to determine your response.  If necessary, contact
        the IBM Support Center for assistance.
        __________________________________________________________
  
  
     B. Change the documentation for message HCP9052W in the CP
        Messages section of Chapter 3 System Messages to add the
        last message variation and last paragraph of the User
        Response as follows:
        __________________________________________________________
  
        HCP9052W  Variations of this message are explained below:
  
                  Error reading PDR from volume <label> for SSI
                  <ssi_name>
  
                  Error updating PDR on volume <label> for SSI
                  <ssi_name>
  
                  PDR volume label not online or not in CP-owned
                  or user volume list
  
                  PDR and defined configurations do not match
  
                  SSI level is incompatible with the SSI cluster
  
                  Cross-system timeout setting is incompatible
                  with the SSI cluster
  
     |            Error upgrading PDR on volume <label> for SSI
     |            <ssi_name>
  
        Explanation: There is a problem with the persistent data
        record (PDR). The system cannot initialize and function as
        part of an SSI cluster.
  
        System Action: The system enters a disabled wait state
        (wait state code = 9052).
  
        User Response: Determine what caused the problem. If
        another member in the SSI cluster is active, make changes
        to fix the problem from that member. If no other member in
        the SSI cluster is active, then re-IPL the local system
        using the REPAIR IPL parameter, fix the problem, and
        re-IPL the system in order for it to join the SSI cluster.
        For more information, see "Overriding Stand-Alone Program
        Loader Defaults".
  
     |  If this message occurred because an error occurred while
     |  trying to upgrade the PDR, use the FORMSSI utility to
     |  manually upgrade the PDR.  If necessary, contact the IBM
     |  Support Center.
        __________________________________________________________
  
  
  2. SC24-6175-04 z/VM: CP Commands and Utilities Reference
  
     Change usage note 3 in the FORMSSI utility documentation
     in Chapter 3 CP Utilities to the following:
  
        3. The PDR structure allows complete forward and backward
           compatibility among different releases of z/VM. This
           compatibility allows the sizes of record structures to
           increase over time using the UPGRADE function. However,
           the UPGRADE function does not accommodate decreasing
           these structure sizes and produces an error message if
           such a change is attempted.
  
     |     z/VM will upgrade the PDR automatically during IPL if
     |     the IPLing system determines that the record structure
     |     supported by the system is larger than the record
     |     structure in the PDR on disk.
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UM34249 UM34250 UM34251 UM34252 306PC1Ÿ

Modules/Macros

• FORMSSI  HCPARD   HCPMES   HCPMESA  HCPMESB
  HCPMXRBK HCPPDF   HCPPDR   HCPPDRBK HCP1635I HCP9052W
  

Fix information

• Fixed component name

  VM CP

• Fixed component ID

  568411202

Applicable component levels

• RA62 PSY UM34249

     UP14/09/10 P 1401

• RA63 PSY UM34250

     UP15/02/16 P 1501

• R620 PSY UM34251

     UP14/02/19 P 1401

• R630 PSY UM34252

     UP14/02/19 P 1401

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.