IBM z13s Technical Manual page 192

Improve utilization of FICON director and ISL
Easier to manage with a predicable and repeatable I/O performance.
FICON dynamic routing can be enabled by definition of dynamic routing capable switches and
control units in HCD. Also, z/OS has implemented a health check function for FICON dynamic
routing.
Improved zHPF I/O execution at distance
By introducing the concept of pre-deposit writes, zHPF reduces the number of round trips of
standard FCP I/Os to a single round trip. Originally this benefit is limited to writes that are less
than 64 KB. zHPF on z13s and z13 servers has been enhanced to allow all large write
operations (> 64 KB) at distances up to 100 km to be run in a single round trip to the control
unit. This process does not elongate the I/O service time for these write operations at
extended distances.
Read Diagnostic Parameter Extended Link Service Support
To improve the accuracy of identifying a failed component without unnecessarily replacing
components in a SAN fabric, a new Extended Link Service (ELS) command called Read
Diagnostic Parameter (RDP) has been added to the Fibre Channel T11 standard. The
command allows z Systems to obtain extra diagnostic data from the Small Form-Factor
Pluggable (SFP) optics located throughout the SAN fabric.
z13s servers now can read this additional diagnostic data for all the ports accessed in the I/O
configuration and make the data available to an LPAR. For z/OS LPARs using FICON
channels, z/OS displays the data with a new message and display command. For Linux on
z Systems, z/VM, z/VSE, and KVM LPARs using FCP channels, this diagnostic data is
available in a new window in the SAN Explorer tool.
N_Port ID Virtualization enhancement
N_Port ID Virtualization (NPIV) allows multiple system images (in LPARs or z/VM guests) to
use a single FCP channel as though each were the sole user of the channel. This feature, first
introduced with z9 EC, can be used with earlier FICON features that have been carried
forward from earlier servers.
Using the FICON Express16S as an FCP channel with NPIV enabled, the maximum numbers
of these aspects for one FCP physical channel are doubled:
1. Maximum number of NPIV hosts defined: Increased from 32 to 64
2. Maximum number of remote N_Ports communicated: Increased from 512 to 1024
3. Maximum number of addressable LUNs: Increased from 4096 to 8192
4. Concurrent I/O operations: Increased from 764 to 1528
For for information about NPIV, see 7.3.40, "N_Port ID Virtualization" on page 267.
Export / import physical port WWPNs for FCP Channels
z Systems automatically assigns worldwide port names (WWPNs) to the physical ports of an
FCP channel based on the PCHID. This WWPN assignment changes when an FCP Channel
is moved to a different physical slot position. z13 and z13s servers will now allow for the
modification of these default assignments, allowing FCP channels to keep previously
assigned WWPNs, even after being moved to a different slot position. This capability can
eliminate the need for reconfiguration of the SAN in many situations, and is especially helpful
on a system upgrade.
For more information about the FICON enhancement of z13 and z13s servers, see Get More
Out of Your IT Infrastructure with IBM z13 I/O Enhancements, REDP-5134.
164
IBM z13s Technical Guide