Schedulers offline

Whilst working with a number of SQL Server Standard edition installations I noticed that some schedulers were offline.

This can be a common problem with your VM configuration assigning the vCPUs as sockets instead of cores.

This is only applicable in Standard Edition.

So you may assign 8 sockets - but only 4 will be used. but if you assigned 8 cores, then all of them should be used.

The more vCPUs the better.

Check the SQL Server licensing for Std Edn - “Limited to lesser of 4 sockets or 24 cores”

https://docs.microsoft.com/en-us/sql/sql-server/editions-and-components-of-sql-server-2016?view=sql-server-2017

You need a good understanding of the definitions of sockets and cores as defined by Microsoft (not easy).

https://docs.microsoft.com/en-us/sql/sql-server/compute-capacity-limits-by-edition-of-sql-server?view=sql-server-2017

You can use the following query to check for offline schedulers:

SELECT * FROM sys.dm_os_schedulers WHERE is_online = 0;