First, some background info: We have a C1000V CPPM 6.7.0 virtual appliance deployed with its default hardware config. Our virtualised infrastructure is becoming oversubscribed and CPU performance is beginning to suffer... we have had an external consultant confirm this for us. CPU ready time (for those familiar with vSphere metrics) is have a negative affect overall. ie. we have too many vCPUs allocated to too many VMs.
I have been requested to resolve this performance issue... without spending money on more hardware.
I intend to reduce vCPU allocation to VMs whose average CPU use is below 20%... eg. a 4vCPU VM with 10% CPU use will be reduced to 2vCPU, for an expected new CPU use of 20%. This will allow the released CPUs to be better used by other VMs that need them.
Now, the question at hand: I would like to reduce the 8vCPU of our C1000V appliance to 4vCPU, and shift its current 7% CPU to approx 14%. Are there any technical reasons that this cannot or should not be done?
I realise this is probably not recommended nor supported... however, we are desperate to improve our CPU usage by better "right-sizing" many of our VMs. If I was to implement this change and later encountered a problem, I assume I would need to reverse it before requesting any official support....?
Thanks for your feedback and advice...
Ashley