IBM z/OS manual Greater than 15 Logical Partitions LP, Physical Channel IDs PCHIDs SubSystem

z990 Logical Channel SubSystems (LCSSs) and support for

greater than 15 Logical Partitions (LP)

In order to provide the increased channel connectivity required to support the scalability of the z990, the z990 channel I/O SubSystem delivers a breakthrough in con- nectivity, by providing up to 4 LCSS per CEC, each of which can support up to 256 CHPIDs with exploitation soft- ware installed. This support is provided in such a way that is transparent to the programs operating in the logical par- tition. Each Logical Channel SubSystem may have from 1 to 256 CHPIDs and may in turn be confi gured with 1 to 15 logical partitions. Each Logical Partition (LPAR) runs under a single LCSS. As with previous zSeries servers, Multiple Image Facility (MIF) channel sharing as well as all other channel subsystem features are available to each Logical Partition confi gured to each Logical Channel SubSystem.

Up tp 30 Logical Partitions

	Up to 256		Up to 256			Up to 256		Up to 256
LCSS0 CHPIDs		LCSS1		CHPIDs	LCSS2	CHPIDs	LCSS3	CHPIDs

Physical Channel IDs (PCHIDs) SubSystem

In order to accommodate the new support for up to 1024 CHPIDs introduced with the Logical Channel SubSystem (LCSS) a new Physical Channel ID (PCHID) is being intro- duced. The PCHID represents the physical location of an I/O feature in the I/O cage. CHPID numbers are no longer pre-assigned and it is now a customer responsibility to do this assignment via IOCP/HCD. CHPID assignment is done by associating a CHPID number with a physical location, the PCHID. It is important to note that although it is pos- sible to have LCSSs, there is still a single IOCDS to defi ne the I/O subsystem. There is a new CHPID mapping tool available to aid in the mapping of CHPIDs to PCHIDs. The CHPID Mapping tool is available from Resource Link™, at ibm.com/servers/resourcelink.

IOCP - IOCDS

		Partitions						Partitions
		LCSS0						LCSS1
	CHPIDs						CHPIDs
4F			12	52	EF	00		02	12	2F	EF

HCD - HSA or IOCDS - HSA

102 103 104 110

200 201 202

2B02C5

Physical Channels (PCHIDs)

Note: Crypto no longer requires a CHPID

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