In this example, three LPARs are defined in the z15 model 403 with two zIIPs. Two zIIPs are  assigned to LPARy and LPARz. During normal operation, all CP work is dispatched at  subcapacity (CP4). Only zIIP eligible work is dispatched to zIIPs.  Note:  Stand-alone memory dump does not use zIIP for boost purposes. Before the planned shutdown of LPARz, the IEASDBS proc is started by an operator or  automation. This process starts the shutdown boost. CP work that is dispatched by LPARz is  run at full-capacity (CP7) and also general-purpose workload is dispatched to zIIPs. LPARx  and LPARy continue in the normal operation at subcapacity (CP4) and only zIIP-eligible  workload is dispatched to zIIP. IBM Geographically Dispersed Parallel Sysplex (GDPS) drives BCPii HW APIs for  orchestrating CBU capacity activations, image activations, resets, and IPLs for multiple  images in many planned and unplanned DR site-switch scenarios. 3 Firmware changes on the z15 HMC and SEs support greater parallelism and performance  improvements in the HW API services. GDPS uses these changes to take advantage of available parallelism in the following  underlying hardware services: System Recovery Boost is a firmware feature of the z15 CPC for operating systems that are  running in an LPAR, which requires operating system support.  Important:  The base System Recovery Boost capability is built into z15 firmware and does  not require ordering extra features. System Recovery Boost Upgrade (consisting of FC  9930 and FC 6802) is an optional, orderable feature that provides more temporary zIIP  capacity for use during boost periods. Consider the following points: You can configure a z/OS system-level parameter (IEASYSxx) to control whether a specific  z/OS image opts in for the zIIP processor Boost, as shown in the following example: BOOST=SYSTEM | ZIIP | SPEED | NONE B.3.5 IBM Geographically Dispersed Parallel Sysplex Actions Performance  and Parallelism B.4 Setting up the System Recovery Boost GLYPH<SM590000> FC 9930 is  not  required to use the base System Recovery Boost capability. GLYPH<SM590000> FC 9930 is  only  needed if more zIIP temporary capacity is required. GLYPH<SM590000> By default, System Recovery Boost is enabled for z/OS (opt-in). z/OS must run on z15  CPC. GLYPH<SM590000> For extra zIIP temporary boost capacity, FC 9930 and FC 6802 (System Recovery  Boost Upgrade) must be ordered with the z15 CPC. 3 z/OS use requires z/OS 2.4 with rollback to 2.3 with PTFs (for subcapacity and zIIP boost, on z15 CPC). 498  IBM z15 (8561) Technical Guide GLYPH<SM590000> GDPS usage that requires GDPS 4.2 GLYPH<SM590000> Firmware support that is delivered on the z15 machine