NUMA and cores per sockets + memory size

plastilin

Active Member
Oct 9, 2012
49
0
26
Ukraine
As far as I understand, when using multiprocessor boards based on Proxmox, you need to use NUMA in virtual machines. Are there any recommendations for enabling NUMA in virtual machines? Perhaps depending on a certain amount of RAM and the number of cores? In what types of machines is it better to use and which not?
 
Mar 23, 2020
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@Alwin According to this documentation
If the NUMA option is used, it is recommended to set the number of sockets to the number of nodes of the host system
Now if I see my hardware
Code:
root@inc1pve17:~# numactl --hardware
available: 4 nodes (0-3)
node 0 cpus: 0 1 2 5 6 7 24 25 26 29 30 31
node 0 size: 46958 MB
node 0 free: 19984 MB
node 1 cpus: 3 4 8 9 10 11 27 28 32 33 34 35
node 1 size: 48376 MB
node 1 free: 18819 MB
node 2 cpus: 12 13 14 18 19 20 36 37 38 42 43 44
node 2 size: 48376 MB
node 2 free: 2009 MB
node 3 cpus: 15 16 17 21 22 23 39 40 41 45 46 47
node 3 size: 48351 MB
node 3 free: 256 MB
node distances:
node   0   1   2   3
  0:  10  11  23  23
  1:  11  10  23  23
  2:  23  23  10  11
  3:  23  23  11  10
So I need to set socket Count as 4 in VM Configuration. Whether my understanding is correct??
 
Last edited:
Mar 23, 2020
190
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I read the documentation. But in it I did not find whether it was necessary to enable NUMA in the advanced virtual CPU options in the settings of the virtual machine itself.
Not mandatory
Read the text below
If your system has a NUMA architecture [33] we recommend to activate the option, as this will allow proper distribution of the VM resources on the host system. This option is also required to hot-plug cores or RAM in a VM.
 

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