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These changes affect the performance management of z/VM and
- Monitor Enhancements
- CP I/O Priority Queueing
- Virtual Machine Resource Manager
- Effects on Accounting Data
- VM Performance Products
There were three major changes to the monitor data for z/VM 4.3.0. The
first two changes were to include additional system configuration
information and also information on the hardware I/O processors. These
changes were specifically made to improve the capability of the
monitor. The third change was the addition of data in support of the
new I/O Priority Queuing function. As a result of these three changes,
there are two new monitor records and several changed records. The
detailed monitor record layouts are found on
our control blocks page.
When VM runs on LPAR, second level on another VM system, or in a
combination of LPAR and second level, it is often valuable to know the
configuration of the underlying hypervisor. In z/VM 4.3.0, CP uses the
STSI (Store System Information) instruction to gather applicable
information about the physical hardware, the LPAR configuration, and
the VM first level system. This additional information can be found in
Domain 0 Record 15 (Logical CPU Utilization Data) and Domain 0 Record 19
Many of the current IBM zSeries servers have I/O processors that
handle various I/O processing tasks. These are sometimes referred to as
System Assist Processors. As more function is implemented in these
extra processors, there is value in knowing the utilization of the
processors. Monitor now collects that information and it can be found
in the new Domain 5 Record 8 (I/O Processor Utilization). A
zSeries server may have more than one I/O processor. A separate
record is created for each I/O processor.
Support was also added in z/VM 4.3.0 to exploit I/O priority queuing.
Information was added to monitor on the system settings and user
settings. Record Domain 0 Record 8 (User Data) includes some system
settings. The user information was added to Domain 4 Record 3
(User Activity Data). Since these settings can be changed by CP
commands or the HMC for system level, Domain 2 Record 11 (I/O Priority
Changes) was created to track these events.
I/O management facilities have been added that enable z/VM to
exploit the hardware I/O Priority Queueing facility to prioritize guest
and host I/O operations. A virtual equivalent of the hardware facility
is provided, allowing virtual machines running guest operating systems
such as z/OS that exploit I/O Priority Queueing to determine the
priority of their I/O operations within bounds defined by a new CP
command. z/VM will automatically set a priority for I/O operations
initiated by virtual machines that do not exploit this function. The
IOPRIORITY directory control statement or the SET IOPRIORITY CP command
can be used to set a virtual machine's I/O priority. For more
information see z/VM: CP Planning and Adminstration and
z/VM: CP Command and Utility Reference.
z/VM 4.3.0 introduces a new function, called the Virtual Machine
Resource Manager, that can be used to dynamically tune the VM system so
that it strives to achieve predetermined performance goals for
different workloads (groups of virtual machines) running on the system.
For further information, refer to the "VMRM SVM Tuning Parameters"
chapter in the z/VM: Performance manual.
None of the z/VM 4.3.0 performance changes are expected to have a
significant effect on the values reported in the virtual machine
resource usage accounting record.
z/VM 4.3.0 introduces a new accounting record (record type C) that
quantifies virtual network traffic (bytes sent and received) for
each virtual machine. The following virtual networks are supported:
VM Guest LAN, virtual CTC, IUCV, and APPC. For further information,
see z/VM: CP Planning and Adminstration.
This section contains information on the support for z/VM 4.3.0
provided by VMPRF, RTM, FCON/ESA, and VMPAF.
VMPRF support for z/VM 4.3.0 is provided by VMPRF Function Level 4.1.0,
which is a preinstalled, priced feature of z/VM 4.3.0. The latest
service is recommended, which includes new system configuration,
LPAR configuration, and I/O processor reports:
SYSTEM_CONFIG_BY_TIME (PRF118) provides information
about the CPU configuration of the monitored VM system.
If the VM system being monitored is being run second level (or
third level, etc.), the CPU configuration of both the first-level VM
system and the monitored VM system are provided.
For VM systems running in an LPAR, LPAR_CONFIG_BY_TIME (PRF119)
provides processor configuration information for that LPAR.
IOPROCESSORS_BY_TIME (PRF120) provides processor utilization and
I/O activity data for each of the I/O processors in the real processor
configuration. Summary (PRF121) and trend (PRF122) records can also be
produced for this data.
VMPRF 4.1.0 can also be used to reduce CP monitor data obtained from
any supported VM release.
RTM support for z/VM 4.3.0 is provided by Real Time Monitor Function
Level 4.1.0. As with VMPRF, RTM is a preinstalled, priced feature
of z/VM 4.3.0. The latest service is pre-installed on z/VM 4.3.0 and is
To run FCON/ESA on any level of z/VM, FCON/ESA Version 3.2.02 or
higher is required. Version 3.2.04 of the program also implements
some z/VM 4.3.0 specific new monitor data; this is the recommended
minimum level for operation with z/VM 4.3.0. The program runs on
z/VM systems in both 31-bit and 64-bit mode and on any previous
Performance Analysis Facility/VM 1.1.3 (VMPAF) will run on z/VM
4.3.0 with the same support as z/VM 4.2.0.
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