[SOLVED] Documentation about smp versus sockets

[leesteken]

The documentation states:

smp: <integer> (1 - N) (default = 1)
The number of CPUs. Please use option -sockets instead.

sockets: <integer> (1 - N) (default = 1)
The number of CPU sockets.

However, using sockets in combination with numa (in order to use hugepages) seems to require matching actual numa nodes on the host (also, numa=fake does not seem to work for my host).
Do the Proxmox developer really prefer 8 sockets (each 1 core) over 8 cores (in 1 socket) in a VM? I would have guesses that it would be the other way around. Can someone enlighten me?

 

[apoc]

I rather think that SMP was the legacy option and sockets is the successor of that option.
There was a time when NUMA didn't exist so it really didn't matter from a hardware/software perspective.
Today that is different. He has "local" and "remote" memory, applications have numa support etc.
Rules of thumb are: don't make a VM larger than a numa node in terms of cores. Match numa nodes in the VM if going beyond. Always use least possible number of cores in VMs

 

[leesteken]

It was thinking similar thoughts. Is this a bug in the documentation or is the remark no longer usefull, and is there a place to report such small issues?

 

[leesteken]

I got confused between smp and cores: sockets should be used instead of smp, not cores.

Feel free to remove this topic...