When you are using VMs with a large amount of memory then NUMA topology becomes important. Hyper-V can reveal the underlying physical NUMA topology to the VM so that the guest OS and NUMA-aware apps (such as SQL Server) efficiently assign memory and schedule processes to make the most of the boundaries.<\/p>\n
There is something important to note. Enabling Dynamic Memory in the settings of a VM disables virtual NUMA. That means that the vast majority of VMs will not have virtual NUMA. To squeeze the best processor\/memory performance out of larger VMs you will need to use static RAM, as noted here<\/a> under Virtual NUMA:<\/p>\n Virtual NUMA and Dynamic Memory features cannot be used at the same time. A virtual machine that has Dynamic Memory enabled effectively has only one virtual NUMA node, and no NUMA topology is presented to the virtual machine regardless of the virtual NUMA settings.<\/p>\n<\/blockquote>\n So you have a balancing act to do:<\/p>\n This is not ideal. Introducing a human decision into a cloud where uneducated \u201cusers\u201d are deploying their own VMs makes things less efficient. Hopefully MSFT will overcome the Dynamic Memory versus virtual NUMA conflict in a future version, but when you think about it, this would difficult to do.<\/p>\n When you are using VMs with a large amount of memory then NUMA topology becomes important. Hyper-V can reveal the underlying physical NUMA topology to the VM so that the guest OS and NUMA-aware apps (such as SQL Server) efficiently assign memory and schedule processes to make the most of the boundaries. There is something … Continue reading “Hyper-V Virtual NUMA Versus Dynamic Memory”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"_wpcom_ai_launchpad_first_post":false,"footnotes":""},"categories":[20],"tags":[181,86,195,118,120],"class_list":["post-15877","post","type-post","status-publish","format-standard","hentry","category-hyper-v","tag-hyper-v","tag-performance","tag-virtualisation","tag-windows-server-2012","tag-windows-server-2012-r2"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n
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