CPU Hot-Add And NUMA

Frank Denneman discusses VMware NUMA behavior when you hot-add more CPUs:

But what happens when the VM is configured with less vCPUs than the core count of the physical CPU package and CPU Hot-Add is enabled? Will there be performance impact? And the answer is no. The VPD configured for the VM fits inside a NUMA node, and thus the CPU scheduler and the NUMA scheduler optimizes memory operations. It’s all about memory locality. Let’s make use of some application workload test to determine the behavior of the VMkernel CPU scheduling.

For this test, I’ve installed DVD Store 3.0 and ran some test loads on the MS-SQL server. To determine the baseline, I’ve logged in the ESXi host via an SSH session and executed the command: sched-stats -t numa-pnode. This command shows the CPU and memory configuration of each NUMA node in the system. This screenshot shows that the system is only running the ESXi operating system. Hardly any memory is consumed. TotalMem indicates the total amount of physical memory in the NUMA node in kb. FreeMem indicates the amount of free physical memory in the NUMA node in kb.

Interesting reading.

Related Posts

Managing Central Management Server

Chrissy LeMaire shows how you can use dbatools to manage Central Management Server and registered servers: It’s a super useful feature that not all DBAs know about. Since CMS data is stored in msdb and accessible via SMO, you can access it from SQL Server Management Studio or PowerShell modules like dbatools. Central Management Server’s essential […]

Read More

Checking File Sizes In SQL Server

Andy Mallon looks back at a contribution by Junior DBA Andy, this one on checking file sizes: This is every DBA’s favorite game. Figuring out what DMV contains the data you want. It turns out there are two places that database file size info is maintained. Each database has sys.database_files which has information for that database. The […]

Read More

Categories

April 2017
MTWTFSS
« Mar May »
 12
3456789
10111213141516
17181920212223
24252627282930