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IJ22714: POSSIBLE UNDETECTED DATA CORRUPTION WHEN RW_MAX_TIME IS NON-ZEROAPPLIES TO AIX 7200-04

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

  • **************************************************************
    * USERS AFFECTED:
    * Systems running the AIX 7200-04-01 Technology Level
    * or VIOS 3.1.1.x
    * with devices.fcp.disk.rte at 7.2.4.0.
      **************************************************************
    * ERROR DESCRIPTION:
    * Possible undetected data corruption can occur on AIX 7.2TL4
    * or VIOS 3.1.1.x only, with disks who have the new
    * rw_max_time attribute set to a non-default value (any value
    * other than 0).
    * The problem can occur because I/Os may return as successful
    * even though the I/Os did not complete successfully.
    * The problem can be avoided by setting rw_max_time to 0, or
    * by applying the fix.
    * The command below to set the rw_max_time to 0 can be done
    * while the disks are in use and does not require reboot.
    *
    * To check if a disk has the rw_max_time attribute and to
    * verify the attribute's value, issue the following command:
    *
    * lsattr -El <hdiskX> -a rw_max_time
    *
    * To set the attribute's value to 0, issue the following
    * command:
    *
    * chdev -l <hdiskX> -a rw_max_time=0 -U
    *
    * Note: On VIOS, both these commands must be run as root
    * using 'oem_setup_env'.
      **************************************************************
    * RECOMMENDATION:
    * Install APAR IJ22714.
    * Prior to fix availability, an interim fix is available from
    * either
    * ftp://aix.software.ibm.com/aix/ifixes/ij22714/
    * https://aix.software.ibm.com/aix/ifixes/ij22714/
    * The ifix can be installed using Live Update (LU).
    * If LU is not used, installation of the ifix requires a
    * reboot.
      **************************************************************
    

Local fix

Problem summary

  • If the new rw_max_time attribute is set to something other than
    the default value of 0, there is a chance that some disk I/O
    may be returned to the caller with good status even though the
    I/O did not actually complete successfully.
    

Problem conclusion

  • Modify disk driver to ensure that all I/O that is returned
    to the caller due to the expiration of rw_max_time is properly
    marked with a clear failure indication.
    

Temporary fix

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

Comments

  • 7200-04 - use AIX APAR IJ22714
    

APAR Information

  • APAR number

    IJ22714

  • Reported component name

    AIX V7.2

  • Reported component ID

    5765CD200

  • Reported release

    720

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Submitted date

    2020-02-12

  • Closed date

    2020-02-12

  • Last modified date

    2020-11-16

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

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

    IJ22715

Fix information

  • Fixed component name

    AIX V7.2

  • Fixed component ID

    5765CD200

Applicable component levels

  • R720 PSY U884021

       UP20/05/04 I 1000 Ž

PTF to Fileset Mapping

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSVEF8","label":"AIX 7.2 Enterprise Edition"},"Platform":[{"code":"PF053","label":"Power Systems"}],"Version":"720","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}}]

Document Information

Modified date:
18 November 2020