IBM z13s, Technical Manual

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IBM z13s Technical Guide
zDAC applies to all FICON features that are supported on z13s when configured as CHPID
type FC. Table 7-32 lists the minimum support requirements for zDAC.
Table 7-32 Minimum support requirements for zDAC
7.3.33 High-performance FICON
zHPF, first provided on System z10, is a FICON architecture for protocol simplification and
efficiency. It reduces the number of information units (IUs) processed. Enhancements have
been made to the z/Architecture and the FICON interface architecture to provide
optimizations for online transaction processing (OLTP) workloads.
When used by the FICON channel, the z/OS operating system, and the DS8000 control unit
or other subsystems, the FICON channel processor usage can be reduced and performance
improved. Appropriate levels of Licensed Internal Code (LIC) are required. Additionally, the
changes to the architectures provide end-to-end system enhancements to improve reliability,
availability, and serviceability (RAS).
zHPF is compatible with these standards:
򐂰 Fibre Channel Framing and Signaling standard (FC-FS)
򐂰 Fibre Channel Switch Fabric and Switch Control Requirements (FC-SW)
򐂰 Fibre Channel Single-Byte-4 (FC-SB-4) standards
The zHPF channel programs can be used, for example, by the z/OS OLTP I/O workloads,
DB2, VSAM, the partitioned data set extended (PDSE), and the z/OS file system (zFS).
At the zHPF announcement, zHPF supported the transfer of small blocks of fixed size data
(4 K) from a single track. This capability has been extended, first to 64 KB, and then to
multitrack operations. The 64 KB data transfer limit on multitrack operations was removed by
z196. This improvement allows the channel to fully use the bandwidth of FICON channels,
resulting in higher throughputs and lower response times.
The multitrack operations extension applies exclusively to the FICON Express8S, FICON
Express8, and FICON Express16S, on the z13, z13s, zEC12, zBC12, z196, and z114
servers, when configured as CHPID type FC and connecting to z/OS. zHPF requires
matching support by the DS8000 series. Otherwise, the extended multitrack support is
transparent to the control unit.
From the z/OS point of view, the existing FICON architecture is called
command mode
and the
zHPF architecture is called
transport mode
. During link initialization, the channel node and
the control unit node indicate whether they support zHPF.
The mode that is used for an I/O operation depends on the control unit that supports zHPF
and its settings in the z/OS operating system. For z/OS use, a parameter in the IECIOSxx
member of SYS1.PARMLIB (
ZHPF=YES or NO ) and in the SETIOS system command controls
whether zHPF is enabled or disabled. The default is ZHPF=NO .
Operating system Support requirements
z/OS z/OS V1R12
a
a. PTFs are required.
Requirement: All FICON CHPIDs that are defined to the same LCU must support zHPF.
The inclusion of any non-compliant zHPF features in the path group causes the entire path
group to support command mode only.