NUMA on single socket - Bad idea?

[harmonyp]

I have a cluster mixed of single and dual socket machines. Is migrating machines from the dual socket machines > single socket with NUMA enabled have any negative effects?

 

[LnxBil]

I have a cluster mixed of single and dual socket machines. Is migrating machines from the dual socket machines > single socket with NUMA enabled have any negative effects?

Single socket does not imply single numa node. The chiplet-design from AMD does indeed have multiple numa nodes on a single CPU. Yet it should pose any problems with NUMA. You will however have problems live migrating from one cpu type to the next. There are posts on the forum about problems migrating from different types and it'll not work with different vendors (e.g. AMD/Intel).

 

[harmonyp]

Single socket does not imply single numa node. The chiplet-design from AMD does indeed have multiple numa nodes on a single CPU. Yet it should pose any problems with NUMA. You will however have problems live migrating from one cpu type to the next. There are posts on the forum about problems migrating from different types and it'll not work with different vendors (e.g. AMD/Intel).

Thank you, yes they are the same AMD EPYC models some in single socket, some dual.

 

[alexskysilk]

afaik there is no harm passing NUMA data to the guest when there is a single node. Given this being an AMD architecture, as @LnxBil pointed out their chips contain multiple nodes anyway so its a pretty good idea to pass NUMA data to the vm even on a single socket host.

 

[LnxBil]

I meant of course

Yet it should <NOT> pose any problems with NUMA.

NOT missing