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IV68445: DOCUMENT HOW TO CHANGE POWER8 ENTERPRISE MACHINES TO SMT8

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APAR status

  • Closed as documentation error.

Error description

  • The new POWER8 based Enterprise machines E870 and E880 can
    support large numbers of CPU cores and LPAR sizes.
    .
    POWER8 LPARs running AIX 6 TL9 SP4 and AIX 7 TL3 SP4 by default
    are SMT=4 (Like POWER7/7+)
    as the IBM policy is not to catch out a customer by invisibly
    switching on new features.
    The POWER8 processor supports the higher Simultaneous Multiple
    Threading with 8 threads at a time (SMT=8).
    .
    Before switching a large LPAR (48 or higher Dedicated or Shared
    Processor cores) to SMT=8, do the following:
    # probevctrl -c trace=off
    # bosboot -a
    .
    Now you can temporarily switch to SMT=8 immediately, as the
    root user, with:
    # smtctl -t 8 -w now
    When the LPAR reboots or system is rebooted it will return to
    SMT=4 or you can use smtctl to immediately set lower SMT
    numbers like 1, 2 or 4.
    .
    Or make the change now and permanently across LPAR reboots or
    system reboots, as the root user, with:
    # smtctl -t 8 -w now
    # bosboot -a
    .
    It is planned for future releases of AIX in 2015, that the
    management of the probevctrl  command will be optimized
    automatically.
    

Local fix

Problem summary

  • Method do change to SMT8 was unclear
    

Problem conclusion

  • Document the method above
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV68445

  • Reported component name

    AIX V7.1

  • Reported component ID

    5765H4000

  • Reported release

    710

  • Status

    CLOSED DOC

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2015-01-09

  • Closed date

    2015-01-09

  • Last modified date

    2015-01-09

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

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

Fix information

Applicable component levels



Document information

More support for: AIX Enterprise Edition

Software version: 710

Operating system(s): AIX

Reference #: IV68445

Modified date: 09 January 2015


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