[CentOS] Missing CPU Cores from 2nd Socket

Thu Jun 16 20:53:13 UTC 2016
De Vito, Carmen (Carmen) <Carmen.DeVito at cchmc.org>

Has anyone else noticed an issue when running CentOS 7.2.1511 on ESXi 6.0, where only the first sockets worth of cores appear to be presented to the kernel?

For example, I've set up a VM on an ESXi 6 node with 2 sockets, each of which has 2 cores attached. Once I start up the server I can see in dmidecode that both sockets are populated, each with a dual-core processor. But, within top, cpuinfo and numactl, I can only see the cores presented from the socket0 chip.

Is there some kind of kernel restriction on multi-socket setups when virtualized?

Carmen De Vito

Senior Linux Analyst