Virtual Routers and VMWare best practices and capacity planning?

[Seth Beauchamp]

I've been looking for any documentation around best practices on deploying virtual routers in VMWare, the 8000v in particular. Things like Should vcpus be 1:1 with physical cores, can we oversubscribe cpu, guidelines about oversubscribing, etc. Has anyone seen anything like that?

[ComputerRick · Accepted solution]

First, if you have a CPU capable of hyper threading, VMWare should show twice as many logical as physical cores.  The core requirements are in vCPUs so it will use a logical core(s). If this is in production and depending on what the performance and load expectations are, as well as licensing, you may not want to oversubscribe. 

The guide states "Oversubscription of host resources can lead to a reduction of performance and your instance could become instable."  Choosing to do so requires monitoring of the VM to ensure that it's not being starved or in contention with other guests.

In short, yes you can oversubscribe but doing so can have negative consequences and the burden is on you to ensure that the device has the resources needed for the load that it has.

Here is the guide:  https://www.cisco.com/c/en/us/td/docs/routers/C8000V/Configuration/c8000v-installation-configuration-guide/m_install_vmware_esxi_environment.html

HTH!  Please mark as the solution if this answers your question.