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Performance Management

These changes affect the performance management of z/VM and TCP/IP VM.

  • Monitor Enhancements
  • CP Control Block Changes
  • QUERY FRAMES Command
  • NETSTAT Command
  • Effects on Accounting Data
  • VM Performance Products

Monitor Enhancements

A number of new monitor fields have been added. Some of the more significant changes are summarized below. For a complete list of changes, see the MONITOR LIST1403 file (on MAINT's 194 disk) for the VM monitor changes and Appendix F of the Performance Manual for changes to TCP/IP Stack application monitor data.

Several changes were made to the monitor in this release for 64-bit support. While the VM control program can run in either 31-bit or 64-bit mode 1 , a common monitor architecture is used. Larger fields were added to accommodate larger storage sizes. These fields can be used when CP is running in either 31-bit or 64-bit mode. The previous, smaller fields remain for compatibility, but are obviously incorrect for the larger storage sizes. While this approach allows some older monitor reduction programs to continue to work, you should see your vendor for any updates to performance products for this new VM release.

Larger fields were added to system, storage, and user domain records to record both virtual and real storage sizes greater than 2G. While virtual pages can reside above the 2G line, there is a requirement for the page to be located below the 2G line for certain CP processing. Fields have been added to the monitor to record the movement across the 2G line for CP. The monitor also records whether a virtual machine has issued the instruction required to enter 64-bit mode.

The data contributed to the monitor data stream by the TCP/IP stack machine were extended for the QDIO support added in TCP/IP Level 3A0. This includes information describing the use of fixed storage pool, PCI rates, and polling process.

APAR VM62794 was opened to correct inaccurate data in monitor record domain 3 record 3. This is the Shared Storage Management record which reports on Named Saved Systems and Discontiguous Saved Segments. Information on the paging activity and page counts for these shared segments is inaccurate without the APAR applied. The APAR is projected to be available on the second RSU for z/VM 3.1.0.

CP Control Block Changes

CP control block layouts are not considered a supported programming interface. However, many customer tools, some used for performance management, use offsets into control blocks to gather information. Changes in the offsets are common for each release and some result in changes to these tools. Most tools of this nature will need to be reviewed this release because of the multitude of changes in control blocks due to 64-bit support. This is true for both 31-bit and 64-bit systems.


The CP QUERY FRAMES command has been enhanced to include additional information when more than 2G of real storage is in use. This information includes the total amount of online and offline storage above the 2G line. Two other values are also reported: the number of pages on the available list and the number of pages that have not yet been initialized. The latter value should only be nonzero for a brief period of time after a system IPL. When VM IPLs, it does not initialize all of storage at once, but just enough to be productive. The remainder of the storage is initialized in the background. QUERY FRAMES will indicate how much storage is left to be initialized.


The NETSTAT command has been enhanced in TCP/IP Level 3A0 in support of the following enhancements: IP Multicasting, Secure Socket Layer (SSL), and Gigabit Ethernet support. The DEVLINKS option includes information on whether multicast support is available for the given link. Information on SSL connections can be see with the CONN option. Also, the NETSTAT POOLSIZE output includes information on the new Fixed Page Storage Pool (FPSP) used with Gigabit Ethernet.

Effects on Accounting Data

None of the z/VM 3.1.0 performance changes are expected to have a significant effect on the values reported in the virtual machine resource usage accounting record.

VM Performance Products

This section contains information on the support for z/VM 3.1.0 provided by VMPRF, RTM/ESA, FCON/ESA, and VMPAF.

VMPRF support for z/VM 3.1.0 is provided by VMPRF 1.2.2. This new VMPRF release also supports VM/ESA 2.3.0 and VM/ESA 2.4.0. Changes have been made to the following reports:


A number of these changes are to accommodate 64-bit mode operation. In addition, there are some new reports:


    SIE rates, spin lock rates


    capacity and space utilization data for page, spool, and dump


    similar to DASD_BY_ACTIVITY and DASD_BY_CONFIG but for other I/O devices

NONDASD SUMMARY and TREND records have been added. Data have been added to the end of many of the existing SUMMARY and TREND records.

RTM support for z/VM 3.1.0 is provided by Real Time Monitor for z/VM 1.5.3. RTM 1.5.3 includes several notable improvements. RTM operation can now be tailored at startup through use of a configuration file, 370 accommodation is no longer necessary, and new QUERY ENVIRONMENT and QUERY LEVEL commands are provided. The same RTM MODULE supports both the 31-bit and 64-bit versions of CP. RTM 1.5.3 does not support earlier VM releases. That support is provided by RTM 1.5.2.

FCON/ESA Version 3.2.02 is required for z/VM 3.1.0. It provides the same information for z/VM that the previous level, FCON/ESA V.3.2.01, does for VM/ESA 2.4.0, plus a number of additional z/VM specific fields for z/VM running in 64-bit mode. Additional fields provided by TCP/IP Level 3A0 are included as well. The new FCON/ESA level still runs on any previous VM/ESA release too, as usual.

Performance Analysis Facility/VM 1.1.3 (VMPAF) will run on z/VM 3.1.0 with the same support as VM/ESA 2.4.0.


These are more formally known as ESA/390 and zArchitecture.

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