How do I know if my server has NUMA?

I'm no expert here, but here's something:

Box 1, no NUMA:

~$ dmesg | grep -i numa[    0.000000] No NUMA configuration found

Box 2, some NUMA:

~$ dmesg | grep -i numa[    0.000000] NUMA: Initialized distance table, cnt=8[    0.000000] NUMA: Node 4 [0,80000000) + [100000000,280000000) -> [0,280000000)

I think this previous question is similar: How to confirm NUMA?

In particular, you can review the NUMA man page here:http://man7.org/linux/man-pages/man7/numa.7.html

And from there you'll see:

$ find /proc -name numa_maps/proc/1/task/1/numa_maps/proc/1/numa_maps/proc/2/task/2/numa_maps/proc/2/numa_maps/proc/3/task/3/numa_maps[etc if you have numa]

And you can get more detail like so:

$ grep NUMA=y /boot/config-`uname -r`CONFIG_NUMA=yCONFIG_K8_NUMA=yCONFIG_X86_64_ACPI_NUMA=yCONFIG_ACPI_NUMA=y$ numactl --hardwareavailable: 2 nodes (0-1)node 0 size: 18156 MBnode 0 free: 9053 MBnode 1 size: 18180 MBnode 1 free: 6853 MBnode distances:node   0   1  0:  10  20  1:  20  10

For Redhat 4,5,6 and 7 systems, one can try the following to determine if NUMA configuration is disabled:

numactl --show does not show multiple nodes

# numactl --showpolicy: defaultpreferred node: currentphyscpubind: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23cpubind: 0nodebind: 0membind: 0

or numactl --hardware does not list multiple nodes

# numactl --hardwareavailable: 1 nodes (0)node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23node 0 size: 524163 MBnode 0 free: 505253 MBnode distances:node   0  0:  10