Asynchronous CF Duplexing enhancement is a general-purpose interface for any CF Lock  structure user. It enables secondary structure updates to be performed asynchronously  regarding primary updates. Initially delivered with CFCC 21 on z13 as an enhanced  continuous availability solution, it offers performance advantages for duplexing lock structures  and avoids the need for synchronous communication delays during the processing of every  duplexed update operation.  Asynchronous CF Duplexing for lock structures requires the following software support: The supported operating systems are listed in Table 7-5 on page 217. Asynchronous XI for CF cache structures enables improved efficiency in CF data sharing by  adopting a more transactional behavior for cross-invalidate (XI) processing, which is used to  maintain coherency and consistency of data managers’ local buffer pools across the sysplex.  Instead of performing XI signals synchronously on every cache update request that causes  them, data managers can “opt in” for the CF to perform these XIs asynchronously (and then  sync them up with the CF at or before transaction completion). Data integrity is maintained if  all XI signals complete by the time transaction locks are released. The feature enables faster completion of cache update CF requests (especially with  cross-site distance that is involved) and provides improved cache structure service times and  coupling efficiency. It requires explicit data manager exploitation and participation, which is  not transparent to the data manager. No SMF data changes were made for CF monitoring  and reporting. Asynchronous CF Duplexing for lock structures Asynchronous cross-invalidate (XI) for CF cache structures GLYPH<SM590000> z/OS V2.3 GLYPH<SM590000> z/OS V2.2 SPE with PTFs for APAR OA47796 and OA49148 GLYPH<SM590000> z/VM V6.4 with PTFs for z/OS exploitation of guest coupling environment GLYPH<SM590000> Db2 12 with PTFs for APAR PI66689 GLYPH<SM590000> IRLM V2.3 with PTFs for APAR PI68378 GLYPH<SM590000> CFCC Level 23 support, plus  GLYPH<SM590000> z/OS PTFs on every exploiting system in the sysplex: GLYPH<SM590000> Fixes for APAR OA54688: Exploitation support z/OS 2.2 and 2.3  GLYPH<SM590000> Fixes for APAR OA54985: Toleration support for z/OS 1.13 and 2.1 GLYPH<SM590000> Db2 V12 with PTFs for exploitation The following requirements must be met: z/VM dynamic I/O configuration support allows you to add, delete, and modify the definitions  of channel paths, control units, and I/O devices to the server and z/VM without shutting down  the system. This function refers exclusively to the z/VM dynamic I/O support of ICA and CE LR coupling  links. Support is available for CS5/CL5 CHPID type in the z/VM dynamic commands,  including the  change channel path dynamic I/O command.  Specifying and changing the system name when entering and leaving configuration mode are  also supported. z/VM does not use the ICA or CE LR features, and does not support the use  of ICA or CE LR coupling links by guests. The supported operating systems are listed in  Table 7-5 on page 217. z/VM Dynamic I/O support for ICA and CE LR CHPIDs Chapter 7. Operating system support  243