11.5 HMC and SE key capabilities 11.5.1 Central processor complex management 11.5.2 LPAR management 428  IBM z14 (3906) Technical Guide The HMC and SE feature many capabilities. This section describes the key areas. For more  information about these capabilities, see the HMC and SE (Version 2.14.0) console help  system or IBM Knowledge Center. The HMC is the primary place for CPC control. For example, the input/output configuration  data set (IOCDS) includes definitions of LPARs, channel subsystems, control units, and  devices, and their accessibility from LPARs. IOCDS can be created and put into production  from the HMC.  The HMC is used to start the power-on reset (POR) of the server. During the POR, processor  units (PUs) are characterized and placed into their respective pools, memory is put into a  single storage pool, and the IOCDS is loaded and initialized into the hardware system area  (HSA). The hardware messages task displays hardware-related messages at the CPC, LPAR, or SE  level. It also displays hardware messages that relate to the HMC. Use the HMC to define LPAR properties, such as the number of processors of each type, how  many are reserved, and how much memory is assigned to it. These parameters are defined in  LPAR profiles and stored on the SE. Because Processor Resource/Systems Manager (PR/SM) must manage LPAR access to  processors and the initial weights of each partition, weights are used to prioritize partition  access to processors. You can use the Load task on the HMC to perform an IPL of an operating system. This task  causes a program to be read from a designated device, and starts that program. You can  perform the IPL of the operating system from storage, the HMC DVD-RAM drive, the USB  flash memory drive (UFD), or an FTP server. When an LPAR is active and an operating system is running in it, you can use the HMC to  dynamically change certain LPAR parameters. The HMC provides an interface to change  partition weights, adds logical processors to partitions, and adds memory. LPAR weights can also be changed through a scheduled operation. Use the Customize  Scheduled Operations task to define the weights that are set to LPARs at the scheduled time. Channel paths can be dynamically configured on and off (as needed for each partition) from  an HMC. The Change LPAR Controls task for z14 servers can export the Change LPAR Controls table  data to a comma-separated value (. csv )-formatted file. This support is available to a user  when they are connected to the HMC remotely by a web browser. Partition capping values can be scheduled and are specified on the Change LPAR Controls  scheduled operation support. Viewing more information about a Change LPAR Controls  scheduled operation is available on the SE. At IBM Knowledge Center, click  IBM Z . Then, click  z14 .