Don’t be that engineer. ✅ Hardware listed on UCS compatibility matrix ✅ ESXi build exactly as per Cisco doc ✅ 1 vCPU per physical core – no overcommit ✅ Memory reservation = full VM memory ✅ Thick eager zeroed disks on low-latency storage ✅ NTP configured inside CUCM OS (not host sync) ✅ DRS set to partially automated or disabled for CUCM VMs Need to Check Your Current Environment? Run this from the CUCM CLI:
Have a war story about a CUCM virtualization requirement you missed? Share it in the comments below. This post reflects best practices based on CUCM 12.x/14.x. Always check the latest Cisco documentation before deployment. cisco cucm virtualization requirements
show status show hardware show version active Then cross-reference with the (you’ll need a Cisco.com login). The Bottom Line CUCM in a VM is incredibly stable—if you follow the rules. Cisco’s requirements aren’t bloated; they exist because UC is real-time, intolerant of jitter, and demands deterministic resources. Don’t be that engineer
Example: If the OVA defines 16 GB RAM, reserve all 16 GB. Share it in the comments below
Let’s break down exactly what you need to know. Cisco publishes a Unified Communications Virtualization Compatibility Matrix (updated quarterly). If your hardware, hypervisor, or CPU isn’t listed there for your specific CUCM version— it is not supported.