In a shared RoCE environment, z/OS® Communications Server uses PCIe Virtual Function (VF) services to manage the RoCE Express® feature, and System z® provides the Physical Function management.
A RoCE Express feature operating in a shared RoCE environment can be shared by up to 31 operating system instances or TCP/IP stacks across the same central processor complex (CPC). Each TCP/IP stack within an LPAR, or each operating system instance, uses a unique FID value to define its representation of the RoCE Express feature. These FID values are defined by using HCD tools. In the shared environment, both RoCE ports can be used at the same time.
Guideline: For a TCP/IP stack, the FID value
is represented by a PFID value on the GLOBALCONFIG statement in the
TCP/IP profile. In addition, the same or different TCP/IP stacks can
share the two RoCE Express ports
of an individual RoCE Express feature
if different PFID values are configured for the individual ports.
Figure 1 is an example of
a 10GbE RoCE Express feature
operating in a shared RoCE environment. Two z/OS images are using the 10GbE RoCE Express features identified
by PCHID values 100 and 200. Four unique PFID values are defined,
two per z/OS image, to represent
the usage of the features. The PFID values correspond to the FID values
defined for the features in the HCD. In this example, the combination
of PFID and port is unique for all four interfaces, but TCP/IP stacks
are sharing the same feature and port.
Figure 1. 10GbE
RoCE Express feature in
a shared RoCE environment
Guideline: For full redundancy
at a TCP/IP stack, configure PFID values that are associated with
physically separate 10GbE RoCE Express features.
For example, in Figure 1,
for z/OS 2, the two features
are in different System z I/O
drawers. Therefore, the failure of one I/O drawer or one feature does
not affect the other I/O drawer or feature.
A shared RoCE environment must be used on the IBM® z13 (z13) or later systems.
