VM65607: LINUX GUEST HANGS DURING I/O STRESS TEST

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• While executing disk I/O stress tests on Linux, the guest became
  unresponsive. The problem could not be resolved without a z/VM
  reIPL.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All zVM users                                *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
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  While executing DASD I/O stress tests, which include cable
  pulls, a Linux guest became unresponsive.  The problem could
  not be resolved without a zVM re-IPL.
  Guest I/O became intermixed with recovery I/O causing the
  I/O queues for the device to become stalled, which in turn
  caused the guest to hang.
  

Problem conclusion

• CP was modified to reduce the priority of certain guest I/O
  operations such that recovery I/O can execute without
  interference.  Guest I/O will be executed after CP recovery
  I/O completes, allowing the guest to continue running.
  

Temporary fix

• FOR RELEASE VM/ESA CP/ESA R540 :
  PREREQ: VM64847 VM64488 VM65367
  CO-REQ: NONE
  IF-REQ: NONE
  FOR RELEASE VM/ESA CP/ESA R620 :
  PREREQ: VM65367
  CO-REQ: NONE
  IF-REQ: NONE
  FOR RELEASE VM/ESA CP/ESA R630 :
  PREREQ: VM65367
  CO-REQ: NONE
  IF-REQ: NONE
  

Comments

APAR Information

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

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

  UM34446 UM34447 UM34448

Modules/Macros

• HCPCUZ   HCPDPD   HCPHPV   HCPPRF
  

Fix information

• Fixed component name

  VM CP

• Fixed component ID

  568411202

Applicable component levels

• R540 PSY UM34446

     UP14/10/09 P 1401

• R620 PSY UM34447

     UP14/10/09 P 1501

• R630 PSY UM34448

     UP14/10/09 P 1501

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.