Draft Document for Review September 23, 2019 1:06 am 8860ch10.fm 10.2 Virtual Flash Memory 10.2.1 VFM overview 10.2.2 Planning for VFM configuration 10.2.3 Configuring VFM This section provides information about the configuration of the Virtual Flash Memory (VFM)  feature on an IBM z15. It covers the following topics: The VFM is the replacement for the Flash Express features that were available on the zEC12,  zBC12, z13, and z13s. VFM offers up to 6.0 TB of virtual flash memory in 512 GB increments.  No application changes are required to change from Flash Express to VFM. VFM is designed to help improve availability and handling of paging workload spikes when  running z/OS V2.1, V2.2, z/OS V2.3, or V2.4. With this support, z/OS is designed to help  improve system availability and responsiveness by using VFM across transitional workload  events such as market openings, and diagnostic data collection. z/OS is also designed to help  improve processor performance by supporting middleware exploitation of pageable large (1  MB) pages. Using VFM can help availability by reducing latency from paging delays that can occur at the  start of the workday or during other transitional periods. It is also designed to help eliminate  delays that can occur when collecting diagnostic data during failures. VFM can also be used  in coupling facility images to provide extended capacity and availability for workloads making  use of IBM WebSpherefi MQ Shared Queues structures. VFM can help organizations meet their most demanding service level agreements and  compete more effectively. VFM is designed to be easy to configure, and to provide rapid time  to value. For more information about the VFM feature, see the  IBM z15 Technical Guide , SG24-8851. For planning considerations, see “Planning considerations for Virtual Flash Memory” on  page 19. The Assignment of VFM to LPARs is exclusively done with the definitions in the image  activation profiles. Note:  Unlike the Flash Express cards, the allocation of VFM to LPARs cannot be altered to  an activated LPAR. So the  Manage Flash Allocation  selection on the HMC is not  supported for z15. GLYPH<SM590000> VFM overview GLYPH<SM590000> Planning for VFM configuration GLYPH<SM590000> Configuring VFM GLYPH<SM590000> VFM management 250  IBM z15 (8561) Configuration Setup