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PJ40711: DASD SSID CHANGE CAUSED A DEVICE TO BE CROSS-LINKED ON TWO SSST CHAINS RESULTING IN A LOOPING ECB AND SYSTEM HANG.

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APAR status

  • Closed as program error.

Error description

  • See Problem Summary.
    

Local fix

  • na
    

Problem summary

  • PAR NUMBER:  PJ40711
    PRODUCT:  z/TPF
    FUNCTIONAL AREA:  RECORD CACHE SUBSYSTEM
    SHIPPED IN PUT:  10
    
    ABSTRACT:
    A DASD subsystem ID (SSID) changed during a VM Hyperswap
    causing a device to be cross-linked on two subsystem status
    table (SSST) chains. This resulted in a CYEA CTL-10 and system
    hang.
    
    PACKAGE CONTENTS:
    Source Segments:
    (C) base/rt/css2.asm
    (C) base/macro/cz1se.mac
    
    Object Only Binaries:
    None.
    
    Configuration Independent Binaries:
    (C) base/load/CSS2.so
    (C) base/obj/css2.o
    
    Support Files:
    base/lst/CSS2.map
    base/lst/css2.lst
    
    OTHER BINARIES TO BUILD: YES
    (C) os390/bin/amx1.pds
    (C) os390/bin/ppcp.pds
    (C) os390/bin/stc.pds
    (C) os390/obj/amx1.o
    (C) os390/obj/ccmcdc.o
    (C) os390/obj/dgr0.o
    (C) os390/obj/sdmu.o
    (C) os390/obj/stcc.o
    (C) os390/obj/stci.o
    (C) os390/obj/stcl.o
    (C) os390/obj/stpp.o
    
    COMMENTS:
    When a VM Hyperswap occurred and switched DASD controllers, a
    state-change-pending interrupt was presented triggering TPF to
    query status. The query returned a different SSID than was
    detected at IPL time when the reporting device was mounted.
    Since the new SSID was not found in the SSST, TPF created a new
    entry and chained the reporting device to it, assuming it was a
    new device entering the configuration for the first time. Since
    the device was already mounted, this action caused it to be
    cross-linked on two SSST chains. A CTL-10 in CYEA occurred
    followed by a system hang, since it was unable to react to
    subsequent state change interrupts. A manual IPL was required.
    

Problem conclusion

  • SOLUTION:
    CSS2.ASM has been modified to check if a device is already
    mounted on another SSST chain, when the SSID reported following
    a state-change is not found in the SSST. If it is already
    mounted, the old SSID and existing SSST slot will be reused to
    avoid cross-linking problems. CSS2.ASM will issue a SNAPC dump
    to capture diagnostic data. An IPL is recommended, at the
    earliest convenience, to rebuild the SSST with the current
    SSIDs.
    
    COREQS: NO
    None.
    
    MIGRATION CONSIDERATIONS: YES
    Functional, automation, and operation changes:
    A new snapc dump, 001245, has been created to report an SSID
    mismatch.
    
    
    
    BUILD COMMANDS AND INSTRUCTIONS: YES
    #maketpf commands for linux
    maketpf -f CSS2 css2.o
    maketpf CSS2 link
    #maketpf commands for z/OS
    maketpf -f amx1 amx1.o
    maketpf -f ppcp ccmcdc.o stpp.o
    maketpf -f stc dgr0.o sdmu.o stcc.o stci.o stcl.o
    maketpf amx1 link
    maketpf ppcp link
    maketpf stc link
    
    UPDATED INFORMATION UNITS: YES
    z/TPF Messages (System Error, Offline, and Program Status Word)
    
    See your IBM representative if you need additional information.
    
    DOWNLOAD INSTRUCTIONS:
    http://www.ibm.com/software/htp/tpf/maint/maintztpf.html
    
    APAR URL:
    http://www.ibm.com/software/htp/tpf/ztpfmaint/put10/PJ40711.htm
    

Temporary fix

Comments

APAR Information

  • APAR number

    PJ40711

  • Reported component name

    Z/TPF

  • Reported component ID

    5748T1501

  • Reported release

    110

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2012-11-07

  • Closed date

    2012-11-27

  • Last modified date

    2012-11-27

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

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

Publications Referenced
SK2T8062        

Fix information

  • Fixed component name

    Z/TPF

  • Fixed component ID

    5748T1501

Applicable component levels

  • R110 PSY UP

       110



Document information

More support for: TPF
z/TPF

Software version: 110

Reference #: PJ40711

Modified date: 2012-11-27