NUMA configuration
Introduction to NUMA architecture
Servers with NUMA
On servers with NUMA architecture, during system boot, the BIOS on some systems will not distribute PCIe slots evenly among the NUMA nodes. Each NUMA node contains multiple CPUs. This imbalanced distribution means that, during high workloads, half or more of the CPUs will remain idle while the rest are 100% utilized. To prevent this imbalance, you must manually assign IO Accelerator devices equally among the available NUMA nodes.
Configuring the IO Accelerator devices for servers FIO_AFFINTIY parameter with the
with NUMA architecture requires the use of the utility.
NUMA node override parameter
The numa_node_override parameter is a list of <affinity specification> couplets that specify the affinity settings of all devices in the system. Each item in the couplet is separated by a colon, and each couplet set is separated by a comma.
Syntax
numa_node_override=<affinity specification>[,<affinity specification>...] Where each <affinity specification> has the following syntax:
Simple example
numa_node_override=fct4:1,fct5:0,fct7:2,fct9:3
has the effect of creating:
Device | Node/group | Process or affinity |
|
|
|
fct4 | node 1 | all processors in node 1 |
fct5 | node 0 | all processors in node 0 |
fct7 | node 2 | all processors in node 2 |
fct9 | node 3 | all processors in node 3 |
Advanced configuration example
This example server has four NUMA nodes with eight
NUMA configuration 57
