SolusVM 2 KVM VMs are not using full capacity of high bandwidth networks (10Gb)

Symptoms 

A maximum of 2 Gbit is reached for a VM.

Cause

Specific adjustments аrе required. Planned to be improved/automated in the scope of SVM2-6344

Resolution

1. Add the following to the /etc/sysctl.conf file:
   

   CONFIG_TEXT: net.core.rmem_max = 16777216
   net.core.wmem_max = 16777216
   net.ipv4.tcp_rmem = 4096 87380 16777216
   net.ipv4.tcp_wmem = 4096 65536 16777216
   net.core.netdev_max_backlog = 5000
   net.core.somaxconn = 1024

   and run:

   # sysctl -p

2. Enable multiqueue in the VM config:
   

   # virsh edit UUID

   and add the following line:

   CONFIG_TEXT: driver name='vhost' queues='4'/
   
   

   Example:
   ...
   <model type='virtio'/>
   <driver name='vhost' queues='4'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
   ... 

    

   Note: Browse to SolusVM 2.0 > Virtual Servers and click on the necessary VPS to see the UUID

3. Restart the VM:

# virsh destroy UUID && virsh start UUID

Uservoice request: Help-us-improve-solus/suggestions/34944721-kvm-multiqueue-support