Cisco maintains one of the most strict—and arguably most misunderstood—virtualization requirement documents in the industry. Ignoring it almost guarantees TAC will hang up on you (politely, but firmly).
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. cisco cucm virtualization requirements
If you’ve ever deployed Cisco Unified Communications Manager (CUCM) in production, you already know: this is not a “throw it on any VMware cluster” situation. Cisco maintains one of the most strict—and arguably
Example: If the OVA defines 16 GB RAM, reserve all 16 GB. The Bottom Line CUCM in a VM is
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.
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:
When in doubt: