: Hypervisor CPU oversubscription or sharing policies across mixed virtual machines are forbidden on primary production nodes. Memory (RAM) Reservation Rules Virtualization for Unified Communications Manager (CUCM)
A 5-second drift between cluster members will break CDR, call history, and failover logic. cisco cucm virtualization requirements
For all production CUCM VMs, you must set: : Hypervisor CPU oversubscription or sharing policies across
show status show hardware show version active if the virtual hardware changes significantly
Cisco mandates for clusters:
: CUCM 12.0 and later use Cisco Smart Software Licensing. Ensure the virtual machine has a stable UUID/MAC address ; if the virtual hardware changes significantly, the license "re-host" may be triggered.