GLYPH<SM590000> Concurrent crossover from Driver level  N  to Driver level  N +1, then to Driver level  N +2,  must be done serially. No composite moves are allowed. GLYPH<SM590000> Disruptive upgrades are permitted at any time, and allow for a composite upgrade (Driver  N  to Driver  N +2). GLYPH<SM590000> Concurrently backing up to the previous driver level is not possible. The driver level must  move forward to driver level  N +1 after EDM is started. Unrecoverable errors during an  update might require a scheduled outage to recover. GLYPH<SM590000> Specific complex code changes might dictate a disruptive driver upgrade. You are alerted  in advance so that you can plan for the following changes: – Design data or hardware initialization data fixes – CFCC release level change GLYPH<SM590000> OSA CHPID code changes might require PCHID Vary OFF/ON to activate new code. GLYPH<SM590000> Crypto code changes might require PCHID Vary OFF/ON to activate new code. The EDM function does not eliminate the need for planned outages for driver-level upgrades.  Upgrades might require a system level or a functional element scheduled outage to activate  the new LIC. The following circumstances require a scheduled outage: Note:  zUDX clients should contact their User Defined Extensions (UDX) provider  before installing Microcode Change Levels (MCLs). Any changes to Segments 2 and 3  from a previous MCL level might require a change to the client’s UDX. Attempting to  install an incompatible UDX at this level results in a Crypto checkstop. 9.9.1 Resource Group and native PCIe MCLs Microcode fixes, referred to as individual MCLs or packaged in Bundles, might be required to  update the Resource Group code and the native PCIe features. Although the goal is to  minimize changes or make the update process concurrent, the maintenance updates at times  can require the Resource Group or the affected native PCIe to be toggled offline and online to  implement the updates. The native PCIe features (managed by Resource Group code) are  listed Table 9-1. Consider the following points for managing native PCIe adapters microcode levels: Table 9-1 Native PCIe cards for z14 GLYPH<SM590000> Updates to the Resource Group require all native PCIe adapters that are installed in that  RG to be offline. For more information about the requirement, see Appendix C, “Native  Peripheral Component Interconnect Express” on page 469. GLYPH<SM590000> Updates to the native PCIe adapter require the adapter to be offline. If the adapter is not  defined, the MCL session automatically installs the maintenance that is related to the  adapter.  384  IBM z14 (3906) Technical Guide Native PCIe adapter type Feature code Resource required to be offline 25GbE RoCE Express2 0430 FIDs/PCHID 10GbE RoCE Express2 0412 FIDs/PCHID zEDC Express 0420 FIDs/PCHID zHyperLink Express 0431 FIDs/PCHID Coupling Express LR 0433 CHPIDs/PCHID