IBM Z10 EC Coupling Facility Configuration Alternatives, System-Managed CF Structure Duplexing

Coupling Facility Configuration Alternatives

IBM offers multiple options for confi guring a functioning Coupling Facility:

•Standalone Coupling Facility: The standalone CF provides the most “robust” CF capability, as the CPC is wholly dedicated to running the CFCC microcode — all of the processors, links and memory are for CF use only. A natural benefi t of this characteristic is that the standalone CF is always failure-isolated from exploiting z/OS software and the server that z/OS is running on for environments without System-Managed CF Structure Duplexing. While there is no unique standalone coupling facility model offered with the z10 EC, customers can achieve the same physically isolated environment as on prior mainframe families by ordering a z10 EC, z9 EC, z9 BC, and z990 with PUs characterized as Internal Cou- pling Facilities (ICFs). There are no software charges associated with such a confi guration.

•Internal Coupling Facility (ICF): Customers consider- ing clustering technology can get started with Parallel Sysplex technology at a lower cost by using an ICF instead of purchasing a standalone Coupling Facility. An ICF feature is a processor that can only run Coupling Facility Control Code (CFCC) in a partition. Since CF LPARs on ICFs are restricted to running only CFCC, there are no IBM software charges associated with ICFs. ICFs are ideal for Intelligent Resource Director and resource sharing environments as well as for data shar- ing environments where System-Managed CF Structure Duplexing is exploited.

System-Managed CF Structure Duplexing

System-Managed Coupling Facility (CF) Structure Duplexing provides a general purpose, hardware-assisted, easy-to- exploit mechanism for duplexing CF structure data. This pro- vides a robust recovery mechanism for failures such as loss of a single structure or CF or loss of connectivity to a single CF, through rapid failover to the backup instance of the duplexed structure pair. CFCC Level 16 provides CF Duplex-

ing enhancements described previously in the section titled “Coupling Facility Control Code (CFCC) Level 16”.

Parallel Sysplex Coupling Connectivity

The Coupling Facilities communicate with z/OS images in the Parallel Sysplex environment over specialized high- speed links. As processor performance increases, it is important to also use faster links so that link performance does not become constrained. The performance, avail- ability and distance requirements of a Parallel Sysplex environment are the key factors that will identify the appro- priate connectivity option for a given confi guration.

When connecting between System z10, System z9 and z990/z890 servers the links must be confi gured to operate in Peer Mode. This allows for higher data transfer rates to and from the Coupling Facilities. The peer link acts simultaneously as both a CF Sender and CF Receiver link, reducing the number of links required. Larger and more data buffers and improved protocols may also improve long distance performance.

				12x
				PSIFB
			Up to 150 meters
				1x
				PSIFB
			Up to 10/100 Km		z10 EC, z10
					BC
				12x
.. .. .. ..				PSIFB
			Up to 150 meters
HCA2-O	HCA2-O LR			z9 EC and z9 BC S07
	.. .. .. ..
	HCA2-O	New ICB-4 cable
	MBA	ICB-4 10 meters		z10 EC, z10 BC, z9 EC,
				z9 BC, z990, z890
				ISC-3
			ISC-3
		IFB-MP	ISC-3
HCA2-C			ISC-3
				Up to 10/100
			ISC-3
				Km
z10 EC		I/O Drawer
				z10 EC, z10 BC, z9 EC,
				z9 BC, z990, z890

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