How do I know if my server has NUMA?

Question

Hopping from Java Garbage Collection, I came across JVM settings for NUMA. Curiously I wanted to check if my CentOS server has NUMA capabilities or not. Is there a *ix command o

Answer 1

You can also just query the information from /sys (this is what tools like numactl do underneath). As others pointed out, using dmesg will be unreliable since it usually does not have unlimited buffering.

To find out how many NUMA nodes are currently available, do:

cat /sys/devices/system/node/online
0-3