VLFDATA subcommand — format virtual lookaside facility data

Use the VLFDATA subcommand to generate diagnostic reports about virtual lookaside facility (VLF) activity in the system. Use the report type parameters to choose the kinds of VLF-related information that you want to see.
  • Syntax
        VLFDATA

    -------- Report Type Parameters -----------------------------

                  [ CLASS(vlfclass) ]  [ ALL ]
                                       [ SHORT ]
                                       [MAJOR(majorname) ]
                                       [MINOR(minorname) ]
                  [ EXCEPTION  ]
                  [ STORAGE [(vlfclass)] ]
                  [ SUMMARY ]
                  [ STATS [(vlfclass)] ]
                  [ USER [(vlfclass)] ]

    -------- SETDEF-Defined Parameters -------------------------
    Note: You can override the following SETDEF parameters.
    See SETDEF subcommand — set defaults.

                   [ ACTIVE | MAIN | STORAGE          ]
                   [ DSNAME(dsname) | DATASET(dsname) ]
                   [ FILE(ddname) | DDNAME(ddname)    ]
                   [ PATH(path-name)     ]
                   [ FLAG(severity) ]
                   [PRINT | NOPRINT ]
                   [ TERMINAL | NOTERMINAL ]
                   [ TEST | NOTEST ]
  • Report Type Parameters

    Use these parameters to select the type of report. If you omit a report type parameter, the default is SUMMARY.

    Note: In the following descriptions, vlfclass is a class name consisting of 1 to 7 alphanumeric characters or the following characters:
    $  (X'5B')
    #  (X'7B')
    @  (X'7C')
    CLASS(vlfclass)
    Requests a report containing information about a VLF object class. Use vlfclass to specify a particular VLF class. You can request the following CLASS reports:
    ALL
    Requests all major/minor information available for the specified class.
    SHORT
    Requests a more detailed version of the SUMMARY report for the specified class.
    MAJOR(majorname)
    Requests a report containing details about all VLF objects associated with the specified major name. Specify this parameter alone or with MINOR. The majorname can consist of up to 64 characters specified in hexadecimal, character, or binary notation.
    MINOR(minorname)
    Requests a report containing information about all VLF objects associated with the specified minor name. Specify this parameter alone or with MAJOR. The minorname can consist of up to 64 characters specified in hexadecimal, character, or binary notation.
    EXCEPTION
    Requests a report containing information about inconsistencies detected during verification of VLF dump data.
    STORAGE [(vlfclass)]
    Requests a report describing the storage management of VLF data spaces. The vlfclass is optional, and specifies the class for which you want to see a STORAGE report. If you do not supply any class names, the report will contain storage information for all classes.
    SUMMARY
    Requests a report containing general information about each class that uses VLF services. The report includes the class type, its status at the time of the dump, related data space information, and some statistics.
    USER [(vlfclass)]
    Requests a report containing information about all identified users for the non-VLF address space that was using a VLF function at the time of error. This non-VLF address space is associated with VLF through use of a user token. The vlfclass is optional; it limits the report to identified users for the specified class.
    STATS [(vlfclass)]
    Requests a report containing statistics. The vlfclass is optional; it limits the report to the specified class.
  • Return Codes

    See Standard subcommand return codes for a description of the return codes produced by the VLFDATA subcommand.

  • Example: See the VLF component in z/OS MVS Diagnosis: Reference for examples of VLFDATA output.