IBM z/OS - page 25

LPAR Support of OSA-Express

For z990 customers or customers who use the Processor

Resource/Systems Manager (PR/SM) capabilities IBM

offers the Multiple Image Facility (MIF), allowing the shar-

ing of physical channels by any number of LPARs. Since

a port on an OSA-Express feature operates as a channel,

sharing of an OSA-Express port is done using MIF. The

LPARs are deﬁ ned in the Hardware Conﬁ guration Deﬁ ni-

tion (HCD). Depending upon the feature, and how it is

deﬁ ned, SNA/APPN/HPR and TCP/IP trafﬁ c can ﬂ ow simul-

taneously through any given port.

IPv6 Support

IPv6 requires the use of an OSA-Express adapter running

in QDIO mode and is supported only on OSA-Express

features on zSeries at driver level 3G or above. IPv6 is

supported on OSA-Express for zSeries Fast Ethernet,

1000BASE-T Ethernet and Gigabit Ethernet when running

with Linux on zSeries, z/VM V5.1, and z/OS V1.4 and later.

z/VM V4.4 provided IPv6 support for guest LANs.

Performance enhancements for virtual servers

Two important networking technology advancements are

announced in z/VM V4.4 and Linux on z990:

• The high performance adapter interrupt handling ﬁ rst

introduced with HiperSockets is now available for both

OSA-Express in QDIO mode (CHPID=OSD) and FICON

Express (CHPID=FCP). This advancement provides a

more efﬁ cient technique for I/O interruptions designed

to reduce path lengths and overhead in both the host

operating system and in the adapter. This beneﬁ ts OSA-

Express TCP/IP support in both Linux for zSeries and

z/VM.

• The z990’s support of virtual machine technology has

been enhanced to include a new performance assist

for virtualization of adapter interruptions. This new z990

performance assist is available to V=V guests (pageable

guests) that support QDIO on z/VM V4.4 and later. The

deployment of adapter interruptions improves efﬁ ciency

and performance by reducing z/VM Control Program

overhead.