VM66907: Z/VM 7.4 CP FIX PACK - FEATURE 03 FIX 03

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• This is Feature Pack 03 Fix Pack 01 for z/VM 7.4.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: 1. All users of the CP AT command            *
  *                 2. Users of the VMRELOCATE command involving *
  *                    a virtual switch connection               *
  *                 3. All users of the z/VM SSI feature         *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  1. ABENDHTT001 HCPXSS+11E0 via the AT command
  ---------------------------------------------
  An AT command may hang if the underlying data transport between
  systems encounters an unrecoverable I/O error. Later, when the
  AT command eventually times out, an HTT001 ABEND is possible due
  to HCPXSS referencing memory that is no longer allocated for the
  AT command's use.
  
  2. GUEST RELOCATION FAILS WITH HCPRLX1937E RC=3034-03.
  ------------------------------------------------------
  In some cases, the VMRELOCATE command fails with message
  HCPRLX1937E and RC=3034-03. That is a reference to error
  HCP3034E which is detected on the destination node when the
  VSWITCH port number is in use by another guest on that node.
  
  3. ISFC message loss may cause link/logon/logoff hang in SSI
  ------------------------------------------------------------
  Some CP commands within an SSI cluster involve resources
  available to other members, so high-priority messages must be
  exchanged with all other members when (for example) a LINK is
  established to a minidisk on a real storage device that is
  available to other SSI members. In some cases, a member of the
  SSI cluster may fail to receive a numbered segment of
  information which results in the high priority queue on the
  ISLINK being blocked. This then prevents the processing of
  subsequent high priority messages which can cause commands to
  hang.
  

Problem conclusion

• 1. ABENDHTT001 HCPXSS+11E0 via the AT command
  ---------------------------------------------
  HCPXSS is updated to recognize when an I/O error of this
  nature has occurred and avoid referencing memory that is
  no longer allocated to it.
  
  2. GUEST RELOCATION FAILS WITH HCPRLX1937E RC=3034-03.
  ------------------------------------------------------
  The logic to COUPLE a relocating user to the destination
  VSWITCH is corrected to recognize that port numbers in the
  upper range are transient and do not have to be preserved
  when reconnecting a virtual NIC.
  
  GC24-6270-74 CP Messages and Codes:
  On Page 673, Variation 3 of message HCP3034E is updated
  as follows:
  - Variation 3
  
  NIC vdev not connected; userid vdev2 is already connected to
  VSWITCH SYSTEM switchname port portnum.
  
  Explanation:
  
  The virtual device address of the adapter (NIC) specified for
  the COUPLE command is not connected because a different virtual
  adapter (identified here by userid vdev2) is already connected
  to the specified port of the virtual switch.
  
  System action:
  
  The command terminates. The COUPLE command is unsuccessful.
  
  User response:
  
  Issue the QUERY VSWITCH command with the PORTNUMBER option to
  display the existing ports or with the DETAILS option to display
  connections. If you specified an incorrect port number, then
  retry the COUPLE command with the correct port number. If an
  incorrect virtual adapter is coupled to this port, you can
  UNCOUPLE the incorrect virtual adapter and then retry the COUPLE
  command. If the correct virtual adapter is coupled to this port,
  you can temporarily uncouple userid vdev2, retry the connection
  that failed and then couple userid vdev2 to the same network
  again.
  
  3. ISFC message loss may cause link/logon/logoff hang in SSI
  ------------------------------------------------------------
  To address the issue, ISFC code is updated to detect a missing
  packet. Code is enhanced to tag packets with a timestamp for
  tracking purposes and reset the link if a sequence number gap
  is detected after some time. Resetting the link allows the
  connections to re-sync and message flow to resume.  The reset
  process may result in a brief period of unresponsiveness but
  connectivity should be restored automatically.
  
  GC24-6270-74 CP Messages and Codes:
  On Page 594, Variation 2 of message HCP2718E is added as
  follows:
  - Variation 2
  
  Link linkname inbound transmission seqno sequence number is
  lost. Link linkname will be reset now.
  
  Explanation:
  
  ISFC detected that a package with sequence number seqno was lost
  in transmission. The receiver and sender channel interfaces
  operate independently, which makes it possible for the receiver
  to rarely miss a transmission and be unable to proceed. This is
  not typically a direct response to user commands but a problem
  that is associated with ISFC activity that might cause a user
  virtual machine to hang or the system to terminate.
  
  System action:
  
  The system automatically resets the link in an attempt to
  prevent virtual machine hangs or system termination. All link
  devices that make up the logical link to system linkname are
  deactivated. Any tasks that use the link are automatically
  terminated. ISFC link devices are re-initialized to restore
  connectivity to the system. Manual intervention is not required.
  
  User response:
  
  No action is required. If re-initialization does not resolve
  connectivity of the link, contact IBM Service.
  

Temporary fix

Comments

APAR Information

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

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

  UM90575

Modules/Macros

• HCPCPE   HCPKCW   HCPMES   HCPMESB  HCPMXRBK HCPNDF   HCPXSS
  HCP2718E HCP3034E 7VMCPR40
  

Fix information

• Fixed component name

  VM CP CP

• Fixed component ID

  568411202

Applicable component levels

• R740 PSY UM90575

     UP25/12/18 I 1000

Fix is available

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