Performance Management
These changes in z/VM 7.3 affect the performance management of z/VM:
- Monitor Changes
- Command or Output Changes
- Effects on Accounting Data
- Performance Toolkit for VM Changes
- Omegamon XE Changes
Monitor Changes
Change in location and size of the MONDCSS and PERFOUT saved segments
The default CP MONITOR MONDCSS saved segment starting virtual address has been changed to 1 GB and the size has been increased to 96 MB. The IBM Performance Toolkit PERFOUT saved segment starting virtual address has been changed to 1120 MB, immediately following the new MONDCSS.
Several z/VM 7.3 enhancements affect CP monitor data. The changes are described below. The detailed monitor record layouts are found on the control blocks page.
Eight member SSI support increases the maximum size of a single system image (SSI) cluster from four members to eight, enabling clients to grow their SSI clusters to allow for increased workloads and providing more flexibility to use live guest relocation (LGR) for nondisruptive upgrade and workload balancing.
The following monitor record has been updated to support Eight member SSI clusters.
| Monitor Record | Record Name |
|---|---|
| Domain 1 Record 25 | SSI Configuration Information |
NVMe emulated device (EDEVICE) support enables NVMe devices that are connected through PCI Express (PCIe) adapters to be defined and managed as Fixed-Block Architecture (FBA) EDEVICEs. All host and guest FBA functions are supported except those functions that require stand-alone support such as warm start and checkpoint. Linux guests that exploit EDEVICEs that are defined on NVMe adapters are not eligible for live guest relocation (LGR). NVMe adapters are available on only LinuxONE servers.
The following monitor records have been updated for this support:
| Monitor Record | Record Name |
|---|---|
| Domain 1 Record 27 | PCI Function Configuration Data |
| Domain 6 Record 24 | SCSI Device Activity |
| Domain 6 Record 39 | PCI Activity |
The following support added for the IBM z16 server includes updates to monitor records:
The Crypto Express8S (CEX8S) adapter is supported as a dedicated or shared resource. Dedicated guests are able to take advantage of all functionality available with the CEX8S adapters, including assorted new enhancements and use of Quantum-Safe APIs.
CPU/Core topology location information is included in z/VM monitor data which provides a better picture of the system for diagnostic or tuning purposes.
The Breaking-event-address register (BEAR) enhancement facility facilitates the debug of wild branches. The instruction simulation count for LPSWEY is added to the monitor records when the BEAR enhancement facility is installed.
The Reset Dynamic Address Translation (DAT) protection facility provides a more efficient way to disable DAT protection, such as during copy-on-write or page-change tracking operations. As a part of this support the simulation count for the RDP instruction is added to the monitor records.
Modifications to the CPU-Measurement Facility introduce a new Counter Second Version Number (CSVN=x'0007') for the machine. The new version number will be supported by z/VM in monitor record Domain 5 Record 13 CPU-Measurement Facility, however, no changes are required because the record uses offset and length fields to describe the counter data. No new fields are added. Previously defined fields are used to relay new information.
The following monitor records have been updated to support the new IBM z16 server:
| Monitor Record | Record Name |
|---|---|
| Domain 0 Record 16 | CPU Utilization Data in a Logical Partition |
| Domain 0 Record 17 | Physical CPU Utilization Data |
| Domain 4 Record 2 | User Logoff Data |
| Domain 4 Record 3 | User Activity Data |
| Domain 5 Record 10 | Crypto Performance Counters |
To provide additional debug information for system and performance problems, z/VM 7.3 updated some monitor records.
The following monitor records have been updated for this support:
| Monitor Record | Record Name |
|---|---|
| Domain 0 Record 2 | Processor Data (Per Processor) |
| Domain 0 Record 10 | Scheduler Activity (Global) |
| Domain 0 Record 20 | Extended Channel Measurement Data (Per Channel) |
| Domain 1 Record 6 | Device Configuration Data |
| Domain 1 Record 7 | Memory Configuration Data |
| Domain 2 Record 4 | Add User to Dispatch List |
| Domain 2 Record 13 | Add VMDBK to the limit list |
| Domain 2 Record 14 | Drop VMDBK from the limit list |
| Domain 3 Record 1 | Real Storage Management (Global) |
| Domain 4 Record 2 | User Logoff Data |
| Domain 4 Record 3 | User Activity Data |
| Domain 6 Record 1 | Vary On Device |
| Domain 6 Record 3 | Device Activity |
| Domain 9 Record 3 | ISFC Logical Link Definition Change |
Command or Output Changes
This section cites new or changed commands or command outputs that are relevant to the task of performance management. It is not an inventory of every new or changed command.
The section does not give syntax diagrams, sample command outputs, or the like. Current copies of z/VM publications can be found in the online library.
VM66534, Crypto Adapter Interrupts
- SET CRYPTO adds operands
- QUERY CRYPTO adds responses
VM66173, Memory Reclamation
- SET STORAGE adds operands
- DEFINE STORAGE adds operands
- QUERY STORAGE adds responses
- SET PAGING adds operands
- QUERY FRAMES adds responses
- QUERY PAGING adds responses
- QUERY SXSSTORAGE adds responses
VM66507, FCP SCSI Path Management
- QUERY EDEVICE adds responses
VM66430, DUMPLOAD Enhancements
- DUMPLOAD adds options
VM66557, VSWITCH Bridgeport Enhancements
- SET VSWITCH adds operands
- QUERY VSWITCH adds responses
z/VM 7.3, NVMe EDEVs
- SET EDEVICE adds operands
- QUERY EDEVICE adds responses
Effects on Accounting Data
z/VM 7.3 did not change accounting.
Performance Toolkit for VM Changes
Performance Toolkit for VM has been enhanced since z/VM 7.2 GA. For details, visit the Perfkit 7.3 page.
Omegamon XE Changes
OMEGAMON XE on z/VM and Linux includes new Java certificates and improvements to the prerequisite checker.
Support for Dynamic Memory Downgrade and Simultaneous Multithreading (SMT) are included with no additional code changes.