– ICA SR fanout layouts and ICA to ICA connections. Use the Resource Link machine information to review the channel configuration. This  process is a normal part of the I/O connectivity planning. The alternative paths must be  separated as far into the system as possible.  When you perform the review, document the resources that can be made available if the EDA  is used. The resources on the drawers are allocated during a POR of the system and can  change after that process. Perform a review when changes are made to z15 servers, such as  adding drawers, PUs, memory, or channels. Also, perform a review when workloads are  added or removed, or if the HiperDispatch feature was enabled and disabled since the last  time you performed a POR. To use the EDA, first ensure that the following conditions are met: 9.8.2 Enhanced drawer availability processing GLYPH<SM590000> Review the system image configurations to determine the resources for each image. GLYPH<SM590000> Determine the importance and relative priority of each LPAR.  GLYPH<SM590000> Identify the LPAR or workloads and the actions to be taken:  – Deactivate the entire LPAR. –C o n f i g u r e  P U s . – Reconfigure memory, which might require the use of reconfigurable storage unit (RSU)  values. – Vary off the channels. GLYPH<SM590000> Review the channel layout and determine whether any changes are necessary to address  single paths. GLYPH<SM590000> Develop a plan to address the requirements. GLYPH<SM590000> Free the used processors (PUs) on the drawer that is removed. GLYPH<SM590000> Free the used memory on the drawer. GLYPH<SM590000> For all I/O domains that are connected to the drawer and ensure that alternative paths  exist. Otherwise, place the I/O paths offline. 396  IBM z15 (8561) Technical Guide