Logical partitions - z13

PR/SM enables the z13 to be initialized for a logically partitioned operation, supporting up to 85 LPARs. Each LPAR can run its own operating system image in any image mode, independently from the other LPARs. An LPAR can be added, removed, activated, or deactivated at any time. Changing the number of LPARs is not disruptive and does not require POR. Certain facilities might not be available to all operating systems because the facilities might have software corequisites. Each LPAR has the same resources as a real CPC: Processors: Called logical processors, they can be defined as CPs, IFLs, ICFs, or zIIPs. They can be dedicated to an LPAR or shared among LPARs. When shared, a processor weight can be defined to provide the required level of processor resources to an LPAR. Also, the capping option can be turned on, which prevents an LPAR from acquiring more than its defined weight, limiting its processor consumption. LPARs for z/OS can have CP and zIIP logical processors. The two logical processor types can be defined as either all dedicated or all shared. The zIIP support is available in z/OS.
The weight and number of online logical processors of an LPAR can be dynamically managed by the LPAR CPU Management function of the Intelligent Resource Director (IRD). These can be used to achieve the defined goals of this specific partition and of the overall system. The provisioning architecture of the z13 adds another dimension to the dynamic management of LPARs. PR/SM is enhanced to support an option to limit the amount of physical processor capacity that is consumed by an individual LPAR when a PU is defined as a general-purpose processor (CP) or an IFL shared across a set of LPARs. This enhancement is designed to provide a physical capacity limit that is enforced as an absolute (versus relative) limit. It is not affected by changes to the logical or physical configuration of the system. This physical capacity limit can be specified in units of CPs or IFLs. The “Change LPAR Controls” and “Customize Activation Profiles” tasks on the Hardware Management Console have been enhanced to support this new function. For the z/OS Workload License Charges (WLC) pricing metric, and metrics that are based on it, such as Advanced Workload License Charges (AWLC), an LPAR defined capacity can be set. This defined capacity enables the soft capping function. Workload charging introduces the capability to pay software license fees based on the processor utilization of the LPAR on which the product is running, rather than on the total capacity of the system: – In support of WLC, the user can specify a defined capacity in millions of service units (MSUs) per hour. The defined capacity sets the capacity of an individual LPAR when soft capping is selected. The defined capacity value is specified on the Options tab in the Customize Image Profiles window. – WLM keeps a 4-hour rolling average of the processor usage of the LPAR. When the 4-hour average processor consumption exceeds the defined capacity limit, WLM dynamically activates LPAR capping (soft capping). When the rolling 4-hour average returns below the defined capacity, the soft cap is removed. For more information about WLM, see System Programmer's Guide to: Workload Manager, SG24-6472. For a review of software licensing, see 7.16.1, “Software licensing considerations” on page 300. Memory: Memory, either main storage or expanded storage, must be dedicated to an LPAR. The defined storage must be available during the LPAR activation. Otherwise, the LPAR activation fails. Reserved storage can be defined to an LPAR, enabling nondisruptive memory addition to and removal from an LPAR, by using the LPAR dynamic storage reconfiguration (z/OS and z/VM).
Channels: Channels can be shared between LPARs by including the partition name in the partition list of a channel-path identifier (CHPID). I/O configurations are defined by the IOCP or the HCD with the CHPID mapping tool (CMT). The CMT is an optional tool that is used to map CHPIDs onto physical channel IDs (PCHIDs). PCHIDs represent the physical location of a port on a card in an I/O cage, I/O drawer, or PCIe I/O drawer. IOCP6 is available on the z/OS, z/VM, and z/VSE operating systems, and as a stand-alone program on the hardware console. HCD is available on the z/OS and z/VM operating systems. Consult the appropriate 2964DEVICE Preventive Service Planning (PSP) buckets before implementation. Fibre Channel connection (FICON) channels can be managed by the Dynamic CHPID Management (DCM) function of the Intelligent Resource Director. DCM enables the system to respond to ever-changing channel requirements by moving channels from lesser-used control units to more heavily used control units, as needed.
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