NUMA configuration

[dkonsmo]

Hello,

Looking for some recommendation for CPU and Memory configuration for a SQL database VM to maintain optimal NUMA performance.  Physical host is the following:

2x  Xeron 4108

160GB Memory

 

The SQL VM in question currently is sized at 4CPU (cores per socket) and 48GB of memory.   If we increased the CPU to 8 what is the best memory configuration? 

 

[cheese2]

I have had the best performance matching the numa architecture of the guest to the numa architecture of the host, or where that isn't possible, one core per socket (so an 8 core VM would have 8 sockets, even though this is an unusual configuration to find in actual hardware).

If you are able, I strongly recommend watching Frank Denneman's excellent presentation "60 Minutes of NUMA" from VMworld 2020 (and I believe 2019 as well) it's deep, dense, and technical, but he lays it all out for you.

[Tibmeister]

Under ESXi 7.x, there really is no need, outside of licensing, to mess with setting more than 1 core per socket and set the socket-count to what you need for CPU's in the VM.  Most CPU's are a single NUMA node nowadays, and anything over 8 vCPU is fully under vNUMA, so I would just set it to one core per socket and 8 sockets and if 48GB is enough RAM, then leave it as is.  Make sure to turn off Hot-Add on both RAM and CPU as this overrides some of the automatic settings.

[dkonsmo]

Would the same apply to ESXi version 6.7?