Highlighted
Expert
Expert

Numa Disabled ?

Hello all,

i have a question regarding the numa. I have a red hat vm ( 5.10 ) , configured right now with 16 vcpu ( 16 sockets , 1 core ).

I have enabled Hot Add memory and Hot Add cpu.

in vmware.log for the vm i see:

2017-02-28T14:24:54.604Z| vmx| NUMA and VCPU hot add are incompatible.  Forcing UMA

so am i correct that in esxtop i should see unnder NHN  -    ?  Right now i see there 0,1

What is more inside the guest i can run numactl and i see this :

img78.png

And now i am bit confused. As per KB:

vNUMA is disabled if VCPU hotplug is enabled (2040375) | VMware KB

Since i have enabled the memory and cpu hot add, i should not see any numa, Numactl says that it has 3 nodes. So now i am even more confused, as in esxtop there visible NHN : 0,1  .

Can somebody correct me in my thinking ?

In ESXTOP present 2 numa nodes, since i have 2 CPU sockets, each with 6 cores , with ht its 12 logical cpu per socket.

esxcli hardware memory get | grep -i numa

   NUMA Node Count: 2

Why in guest o/s i see 3 numa nodes ? First this is that i would expect to see 2, but since the hotplug is turned on , i would expect to see  none ?

If i change the number of vcpu in VM to 12 , then numactl is reporting 2 nodes .

Any chance , somebody could explain this to me, or point me to some documentation that explain this in detail ?

Many thanks.

--- @blog https://grzegorzkulikowski.info
0 Kudos
0 Replies