CPU schedulers offline

Whilst doing a pre-production health check on a SQL Server 2016 Standard Edition server I noticed that some cpu schedulers were offline.

I ran the following query against the DMV sys.dm_os_schedulers.

SELECT * FROM sys.dm_os_schedulers;

This showed that 4 where online and 4 offline.

So SQL Server was only using 4 of the 8 schedulers.

Checking the SQL Server licensing for Standard Edition - “Limited to lesser of 4 sockets or 24 cores”.

I raised this with the infrastructure engineer who found out that the default setting in VMware is to assign all vCPUs as sockets instead of cores. So they adjusted the cores/sockets on this VM to be 1 socket with 8 cores and now SQL Server is using all the available schedulers.