A fix is available
APAR status
Closed as program error.
Error description
Problem with CP FLASHCOPY moving multiple fullpack minidisks to a single larger real volume. Unable to read label on minidisks once relocated to target real device. This occurs on any minidisk moved to a target offset other than real cylinder 0. CP FLASHCOPY usage note indicates that mixing of non-FP & FP minidisks is not supported. However, it would be great to get this working. It is a valuable use case and considered a defect here.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of z/VM FLASHCOPY are affected * **************************************************************** * PROBLEM DESCRIPTION: * **************************************************************** * RECOMMENDATION: APPLY PTF * **************************************************************** The external symptom of the problem is that when fullpack minidisks are consolidated onto a larger volume, their data tracks and data records may not be able to be accessed, as when a process goes to obtain one of said tracks or records, they will not be addressed correctly due to an oversight in CP FLASHCOPY. The problem can be recreated by using CP FLASHCOPY to consolidate multiple fullpack minidisks onto a larger volume. Once this has been done, attempt to access a data record on any of the cylinders that isn't on the first minidisk in this volume. This will result in an incorrect record being accessed or a 'record not found' error. This fault is due to the way that flashcopy addresses the minidisks when it transfers them over. In every case, record zero on each data track will contain the cylinder number relative to the entire storage device to which the minidisks have been transferred. Before this fix, all of the data records were addressed this way due to flashcopy, but with the fix, the remaining data records are addressed relative to the minidisk to which they belong. Example: On the new storage device, we have the 3340th cylinder, which is referenced as such in every data record in every data track contained within the cylinder. Each minidisk has 3339 cylinders, so this is the 1st cylinder on the 2nd minidisk. Code that used to refer to said cylinder cannot find it, because every record says it is on cylinder 3340, and this code is searching for cylinder 1. The true cylinder number (3340) is only recorded on data record 0 of each data track after the fix.
Problem conclusion
Module HCPNFC was updated to turn on the 'force relocation' bit when the failing use case is recognized. The use case is when multiple fullpack minidisks are consolidated onto a single larger real volume. Also, updated the VM FLASHCOPY VDEV command description in the CP COMMAND AND UTILITIES REFERENCE to note that a fullpack minidisk may be copied to a non-fullpack minidisk for the purpose of storage consolidation. This was reflected in usage note 4.
Temporary fix
FOR RELEASE VM/ESA CP/ESA R640 : PREREQ: VM66029 VM66153 CO-REQ: NONE IF-REQ: NONE FOR RELEASE VM/ESA CP/ESA R710 : PREREQ: NONE CO-REQ: NONE IF-REQ: NONE
Comments
APAR Information
APAR number
VM66112
Reported component name
VM CP
Reported component ID
568411202
Reported release
640
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2018-01-02
Closed date
2018-11-09
Last modified date
2019-03-22
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UM35390 UM35391
Modules/Macros
FLASHCOP HCPNFC VDEV
SC24617513 | SC24626810 |
Fix information
Fixed component name
VM CP
Fixed component ID
568411202
Applicable component levels
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.
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Document Information
Modified date:
22 March 2019