Saturday, 20 February 2016

Part 2. What is vNUMA


What is vNUMA?
Please refer below link
Best practice for vNMUA
When creating a virtual machine you have the option to specify the number of virtual sockets and the number of cores per virtual socket. If the number of cores per virtual socket on a vNUMA enabled virtual machine is set to any value other than the default of one and that value doesn’t align with the underlying physical host topology, performance might be slightly reduced.
Therefore, for best performance, if a virtual machine is to be configured with a non-default number of cores per virtual socket, that number should be an integer multiple or integer divisor of the physical NUMA node size
Enhancement in vSphere 6.0
When a vNUMA VM with the hot add memory option is enabled and memory is hot added to it, the newly added memory is now allocated equally across all NUMA regions. In earlier release of vSphere, all new memory was allocated only to region 0. This enhancement ensures that all regions benefit from the increase of RAM, enabling the VM to scale without requiring any downtime
Below are some important points relating to vNUMA:
·         The hypervisor must run vSphere 5.0 and above.
·         The hypervisor must contain NUMA-enabled hardware.
·         vNUMA requires VMs to run virtual hardware version 8 or above.    vNUMA is automatically enabled for VMs with more than 8 x vCPUs
·         To enable vNUMA on VMs with 8 x vCPUs or less, it must be done manually. It can be set in the VM’s Configuration Parameters.
·         vNUMA will not be run on a VM with vCPU hotplug enabled, in fact, the will use UMA with interleaved memory access instead.
·         A VM’s vNUMA topology is set based on the NUMA topology of the hypervisor it is running on. It retains the same vNUMA topology of the hypversior it was started on even if is migrated to another hypervisor in the same cluster. This is why it is good practice to build clusters with identical physical hosts/hardware.


No comments:

Post a Comment