total number of cores != vCPUs if there is more than one socket configured. according to the redhat docs it should be vCPUs not cores:
> Multi-queue virtio-net provides the greatest performance benefit when: > [..] > - The number of queues is equal to the number of vCPUs. https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/virtualization_tuning_and_optimization_guide/sect-virtualization_tuning_optimization_guide-networking-techniques#sect-Virtualization_Tuning_Optimization_Guide-Networking-Multi-queue_virtio-net Signed-off-by: Stefan Sterz <s.st...@proxmox.com> --- qm.adoc | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/qm.adoc b/qm.adoc index 1170dd1..8630419 100644 --- a/qm.adoc +++ b/qm.adoc @@ -770,14 +770,15 @@ vhost driver. With this option activated, it is possible to pass _multiple_ network queues to the host kernel for each NIC. //https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Virtualization_Tuning_and_Optimization_Guide/sect-Virtualization_Tuning_Optimization_Guide-Networking-Techniques.html#sect-Virtualization_Tuning_Optimization_Guide-Networking-Multi-queue_virtio-net -When using Multiqueue, it is recommended to set it to a value equal -to the number of Total Cores of your guest. You also need to set in -the VM the number of multi-purpose channels on each VirtIO NIC with the ethtool -command: +When using Multiqueue, it is recommended to set it to a value equal to the +number of vCPUs of your guest. Remember that the number of vCPUs is the number +of sockets times the number of cores configured for the VM. You also need to set +the number of multi-purpose channels on each VirtIO NIC in the VM with this +ethtool command: `ethtool -L ens1 combined X` -where X is the number of the number of vcpus of the VM. +where X is the number of the number of vCPUs of the VM. You should note that setting the Multiqueue parameter to a value greater than one will increase the CPU load on the host and guest systems as the -- 2.39.2 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
