Downsides to enabling NUMA / hotplug memory and/or CPU?

Colin 't Hart

Renowned Member
Jan 20, 2017
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Frösön, Sweden
www.hiawathaavenue.com
I use Proxmox extensively in my homelab where I have virtual machines for many of my clients (I'm a freelance Postgres DBA and need to keep development / scratch machines separate).

It would be nice to be able to grow and shrink resource usage even more and it got me wondering about hotplug memory and CPU. I discovered that NUMA needs to be enabled in order for this to work. The help indicates that performance can actually improve with NUMA enabled, but I wonder, are their any downsides? If there are none, why isn't it enabled by default?