OA17114: IRA400E 04,PAGEABLE STORAGE SHORTAGE HIGH VIRTUAL STORAGE FIXED IN "ABOVE" FRAMES INSTEAD OF "HIGH" FRAMES

A fix is available

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Customer experiences IRA400E 04,PAGEABLE STORAGE SHORTAGE
    messages.  The "04" indicates an excessive amount of fixed
    frames above the line (but below the bar).  This condition leads
    to the system being hung for minutes at a time.  Extreme
    conditions can lead to a system outage.
       An SVC dump or Standalone dump during this timeframe shows
    that most of the above the line fixed frames are actually
    for highvirt (above the bar virtual) storage addresses.
    Therefore, the storage could have been fixed to high frames
    instead.  However, due to heavy use of high (above the
    bar) frames, few frames in this less restrictive area are
    unallocated.  Therefore, RSM uses available "above" frames
    instead.
       This problem has been seen in environments where DB2 is using
    high virtual storage for its bufferpools and PGFIX(YES) is
    specified for these buffer pools.  In these cases, DB2 typically
    owns a very significant percentage of the high virtual storage
    fixed to below frames.  However, the problem can be exposed by
    any function which does a large amount of fixing of high
    virtual storage.
    ..
    Verification Steps:
    1) IRA400E RC4 (RC04) Pageable Storage Shortage msgs received
    2) SVC dump or SAdump at time of problem shows:
         a. Large amount of fixed above the line frames holding
            high virtual storage
         b. Some above the bar frames are fixed, but many more are
            pageable.
    ..
    Note: To determine the amount of fixed above the line frames
    holding high virtual storage, do the following under IPCS:
     - RSMDATA REALFRAME RA(1000:7FFFF) ALL
     - SORT 81 85   to sort the data by fixcount
     - Delete or exclude all lines that have fixcount of 0000
       (but don't remove lines that have fixcount of 0000i).
       Remove other extraneous lines from report as well.
     - Now you have the list of above the line fixed frames
     - SORT 42 58   to sort the data by virtual address
     - From bottom of report: FIND '0' 49 PREV .  All entries below
       this line are fixed above frames that hold highvirt storage.
       Note the quantity, and the jobname(s) holding the most.
    ..
    Similar techniques can be applied to above the bar frames, but
    if all you want to do is find out how many above the bar frames
    are fixed, how many are allocated, and what the fixed and in use
    (allocated) percentages are, use: IPCS RSMDATA   without
    additional keywords.
    ..
    NOTE: For IRA400E,03 indicating a shortage of pageable storage
    below the line, see APAR OA19055.
    ..
    Additional symptoms: PAGEFIX
    

Local fix

  • For cases where DB2 is the primary owner of above the line fixed
    storage for high virtual buffer pool requests, specifying
    PGFIX(NO) for the bufferpools may provide relief.
    ..
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: Users of HBB7705 and up                      *
    *                 in z/Architecture.                           *
    *                 PTFs will be provided for                    *
    *                 HBB7709 and up.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: IRA400E 04,Pageable storage shortage    *
    *                      high virtual storage fixed in "ABOVE"   *
    *                      frames instead of "HIGH" FRAMES         *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Customer experienced pageable storage shortage
    indicated by IRA400E 04 message.
    The "04" indicates an excessive amount of fixed
    frames above the line (but below the bar).
    Most of the above the line fixed frames are actually
    for highvirt (above the bar virtual) storage addresses.
    Therefore, the storage could have been fixed in high frames
    instead.  However, due to heavy use of high (above the
    bar) frames, few frames in this less restrictive area are
    available. Therefore, RSM uses available "above" frames
    instead.
    Also some customers experienced IRA400E 03,pageable storage
    shortage fixed in "BELOW" frames instead of "HIGH"
    frames.
    

Problem conclusion

  • Code is changed to attempt to fix high virtual pages
    in above the bar frames. If no high frames are available, it
    will search for pageable high frames and try to exchange them
    with below the bar frames. Then it will use these high
    frames to satisfy the highvirt (above the bar virtual) fix
    request. If a high pageable frame can't be found within the
    search time allowed, the code will get an "ABOVE" frame to
    satisfy the high virtual fix request.
    This fix will reduce the possiblity of having the
    IRA400E 04 or 03,pageable storage shortage fixed in "BELOW" or
    "ABOVE" frames instead of "HIGH" frames.
    
    z/OS Data Areas Vol 4 (GA227584) is changed as follows for
    HBB7709 and HBB7720:
    
    RIT Map:
    
      340   (154) UNSIGNED  4   RITQDPREFSTEALCOUNT
                                        Count the number
                                        of times a quad group
                                        was created from Pref
                                        frames
    | 344   (158) CHARACTER 148 *       RESERVED
    | 492   (1EC) ADDRESS   4   RITPFTHC HIGH FRAME CURSOR
      496   (1F0) SIGNED    4   RITSPLN LENGTH OF STACK
                                        to START OF THE
                                        SPECIAL STACK SECTION
    
    RIT Cross Reference:
    
     RITPFTEC      12C
    |RITPFTHC      1EC
     RITPHFQF      59C
    
    
    z/OS Data Areas Vol 4 (GA227584) is changed as follows for
    HBB7730:
    
    RIT Map:
    
      280   (118) UNSIGNED  4   RITQDPREFSTEALCOUNT
                                        Count the number
                                        of times a quad group
                                        was created from Pref
                                        frames
    | 284   (11C) CHARACTER 144 *       RESERVED
    | 428   (1AC) ADDRESS   8   RITPFTHC HIGH FRAME CURSOR
      436   (1B4) SIGNED    4   RITSPLN LENGTH OF STACK
                                        to START OF THE
                                        SPECIAL STACK SECTION
    
    
    RIT Cross Reference:
    
      RITPFTEC      EC
    | RITPFTHC      1AC
      RITPHFQSPLITINPROG
                    6       08
    
    
    z/OS Data Areas Vol 4 (GA227584) is changed as follows for
    HBB7740:
    
    RIT Map:
    
      304   (130) Address   8    RITLFGroupCursor
                                        Address of the Pfte
                                        of the last allocated
                                        large frame group
    
    | 312   (138) CHARACTER 116 *       RESERVED
    | 428   (1AC) ADDRESS   8   RITPFTHC HIGH FRAME CURSOR
      436   (1B4) SIGNED    4   RITSPLN LENGTH OF STACK
                                        to START OF THE
                                        SPECIAL STACK SECTION
    RIT Cross Reference:
    
      RITPFTEC      EC
    | RITPFTHC      1AC
      RITPHFQSPLITINPROG
                    6       08
    

Temporary fix

  • *********
    * HIPER *
    *********
    

Comments

APAR Information

  • APAR number

    OA17114

  • Reported component name

    5752 REAL STOR

  • Reported component ID

    5752SC1CR

  • Reported release

    720

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2006-06-27

  • Closed date

    2007-05-31

  • Last modified date

    2007-07-03

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

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

    UA34631 UA34632 UA34633 UA34634

Modules/Macros

  • IARRCA   IARRIT   IAXENDIN IAXGETFR IAXMI
    IAXRS    IAXUA    IAXVH    IAXVQ
    

Publications Referenced
GA22758400        

Fix information

  • Fixed component name

    5752 REAL STOR

  • Fixed component ID

    5752SC1CR

Applicable component levels

  • R709 PSY UA34631

       UP07/06/13 P F706

  • R720 PSY UA34632

       UP07/06/13 P F706

  • R730 PSY UA34633

       UP07/06/13 P F706

  • R740 PSY UA34634

       UP07/06/13 P F706

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.



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Document information


More support for:

z/OS family

Software version:

720

Operating system(s):

MVS, z/OS

Reference #:

OA17114

Modified date:

2007-07-03

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