Performance Improvements
Large Enhancements
With the change to continuous delivery, IBM has shipped most of the recent new z/VM function as PTFs to z/VM 7.2 instead of waiting for a release boundary. We evaluated some of those PTFs and wrote articles about them. For more information, refer to our z/VM 7.2 page.
Some z/VM 7.2 PTFs providing performance or capacity improvement were not evaluated for this report. Those were:
VM66201: Allow VM Data Space use in Z/Architecture.
VM66386: VARY Command Performance Improvements (also apply VM66438)
VM66421: Allow HyperPAV 1-END Minidisks
VM66430: Add DISTILL Option to Dumpload
VM66450: Non-fullpack Minidisk z/HPF I/O Support
VM66456: Incorrect Paging Device Balancing
Small Enhancements
In our considerations chapter we mentioned some changes clients might like to consider before they migrate to z/VM 7.3. For details, refer to that chapter.
Service Since z/VM 7.2
z/VM 7.3 contains a number of performance-related repairs that were first shipped as service to earlier releases. Because IBM refreshes this report only occasionally, IBM has not yet had a chance to mention these PTFs.
VM66471: D6 R24 Monitor Record Shows Data For Only One Path
VM66501: Performance Toolkit Divide Exception at FCXPRC+30EC
VM66543: Perfkit FCX328 Panel Service Inuse Column In Error
Miscellaneous Repairs
IBM continually improves z/VM in response to customer-reported or IBM-reported defects or suggestions. In z/VM 7.3 the following small improvements or repairs are notable:
FCX127 URESP and FCX129 UTRANS show wrong values with FC UCLASS: The wrong values are repaired.
Perfkit takes a divide exception: The reason for the exception was repaired.
Perfkit FCX100 CPU rows missing: The reason for the missing rows was repaired.
Perfkit support for z/XC virtual machines: Perfkit now displays "z/XC" in appropriate spots.
Perfkit FCX301 DSVBKACT is missing the master-Only DV: The report has been corrected.
Perfkit FCX108, FCX168, FCX329 are missing EDEVs: The reports have been corrected.
Perfkit FCX249 and FCX250 use wrong field for percent connect: The reports have been corrected.
Perfkit FCX132 UCOMM takes a program check: The reason for the program check has been corrected.
z/VM TCP/IP SSL did not use crypto adapters: The reason was found and repaired.
D9 R3 MRISFILC is missing certain error codes: The LDVREASON and LDVERROR codes were added.
D6 R24 MRIODSZI Has Many Errors: Many fields in D6 R24 MRIODSZI are repaired.
D0 R10 MRSYTSCG comments need help: The comments on SRMABSDL and SRMRELDL are repaired.
D0 R10 MRSYTSCG comments need help: The comments on SRMABSDL and SRMRELDL are repaired.
Several Monitor records are missing definitions of EDEVTYPE bits: Comments in MRIODDEV, MRIODVON, and MRMTRDEV comments were improved.
D6 R1 MRIODVON is missing EDEVTABL: The missing field was added.
D2 R13 MRSCLALL and D2 R14 MRSCLDLL are missing VMTODLM and VMTODIL: The missing fields were added.
D0 R20 MRSYTEPM is missing CMGP: The missing field was added.
D1 R6 MRMTRDEV RDEVMEXT comment is unclear: The comment was improved.
D5 R9 MRPRCAPM timings unclear: The timings were corrected.
D0 R16 MRSYTCUM and D0 R17 MRSYTCUP topology comments unclear: The comments were corrected.