CUCM 11 Cluster Design

[guy.richard]

Hi,

I'm just designing a CUCM 11x cluster and have to reserve virtualization resources from my Customer.

In Collab SRND 11x it is written (chapter 25)  that a 2500 users VM needs: 

2,500 users

– 4 vCPU  ??????

– 6 GB vRAM

– 80 GB vDisk

If I use "Collaboration Virtual Machine Placement Tool" 2500 users VM needs only   1 vCPU

Which one is the good answer ?

[Chris Deren]

You can get all virtualization specs for all UC applications here:

http://docwiki.cisco.com/wiki/Unified_Communications_Virtualization_Downloads_(including_OVA/OVF_Templates)

[guy.richard]

OK so you confirm SRND is wrong ?

[Rob Huffman]

Hi Guy,

In this case (as my friend Chris nicely noted +5) the SRND does appear to have a misprint on this design topic. I would go with 2 - vCPU as discussed in this more accurate note from the link he provided;

Notes on 2500 user VM configurations

Note:

The 2500 user VM configuration with one vcpu may exhibit performance issues during CPU/IO-intensive operations (such as installs, upgrades, backups and CDR writes), or if your deployment has certain characteristics such as a large quantity of TFTP files. Changing the VM config to 2 vcpu is recommended as a prevention strategy. Otherwise you may deploy with one vcpu and be TAC-supported, but note that if the root cause of performance issues is found to be insufficient vcpu, Cisco TAC will ask that you change this to 2 vcpu. If your deployment is not experiencing any issues you are not required to change to 2 vcpu and may remain on 1 vcpu.

• Use for publishers, subscribers, standalone TFTP, standalone multicast MOH nodes.ELM or PAWS-M
• User count based on:
  • 1 device per user
  • 2.5K phones per VM
  • 10K max phones per cluster
  • 15K max BHCC per VM
  • 60K max BHCC per cluster
  • Your design/results may vary

Cheers!

Rob