I kept running into problems I've never seen before, such as the lovely VMware "pink screen" (Pink Screen Of Dead). Consistent high CPU usage on UCM and UCCX, etc.
I couldn't find the pattern of "pink screen". But it happens quite a couple time, which I've never seen in the past 8 years with Cisco UC on VMware.
The other issue is high CPU on UCM and UCCX. The CPU usage was consistently at 99% that I couldn't even log into CLI.
Just FYI that that server is a HP DL380 G5 with 32G of RAM and 8x146G SAS drives (a.k.a. Cisco MCS-7845-H2).
Did some research online. The culprit seems to be the Cisco OVA file. Somehow the OVA works fine on ESXi 5.0 but not ESXi 5.5. The solution is NOT to use the OVA. Instead of importing the OVA, I manually created the virtual machine with the specification in OVA.
CUCM:
1 CPU 1 Core
4G RAM
80G HDD
LSI Logic Parallel
VMXNET 3 NIC
UCCX:
1 CPU 2 Core
8G RAM
146G HDD
LSI Logic Parallel
VMXNET 3 NIC
Things seem to be much better now. CPU is around 10%. Maybe it's just me. But if you're running into the same issue, it's worth trying. You don't have to reinstall the VM. Just create a VM from scratch (without using OVA). Then point the hard drive to the existing VM.
This is CPU utilization with fresh created OVA. After the system "warmed up" (about 30 minutes), utilization drops from 99% to 10%.
Some reference links:
http://ciscocollab.wordpress.com/2014/01/28/esxi-5-5-support-latest-information/
http://docwiki.cisco.com/wiki/Unified_Communications_in_a_Virtualized_Environment
https://communities.vmware.com/thread/459962
