{"id":15550,"date":"2013-10-09T09:41:48","date_gmt":"2013-10-09T08:41:48","guid":{"rendered":"https:\/\/aidanfinn.com\/?p=15550"},"modified":"2013-10-09T09:41:48","modified_gmt":"2013-10-09T08:41:48","slug":"kb2885465-cpu-not-allocated-correctly-vms-on-win8-or-ws2012-hyper-v","status":"publish","type":"post","link":"https:\/\/aidanfinn.com\/?p=15550","title":{"rendered":"KB2885465 – CPU Not Allocated Correctly VMs On Win8 Or WS2012 Hyper-V"},"content":{"rendered":"

Microsoft has released a KB article<\/a> for when CPU resources are not allocated correctly for a virtual machine running on Windows 8 Client Hyper-V or Windows Server 2012 Hyper-V.<\/p>\n

This article is related to unexpected behaviour with the virtual processor resource control settings of a VM in Hyper-V.  Most people never touch these settings, and probably aren\u2019t even aware of what they do.  My guess is the only people who touch them are maybe<\/em> hosting companies, and those who want to dedicate processor to SQL Server, Exchange, or SharePoint VMs by reserving 50% or 100% of a logical processor (physical core, or half core with Hyperthreading enabled) capacity to each vCPU in the VM.  That\u2019s probably why this article has appeared now rather than a long time ago.<\/p>\n

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Symptoms<\/u><\/strong><\/p>\n

When the Hyper-V role is installed on a Windows Server 2012-based computer, or the Hyper-V feature is enabled on a Windows 8-based computer, you experience the following issues. <\/p>\n

Issue 1<\/h6>\n

When you set the CPU limit on a virtual machine to a value that is 15 percent or less of the total CPU resources on the computer, the virtual machine crashes.
Note<\/b> This issue does not occur when the virtual machine is running Windows 8, Windows Server 2012, or a later version of Windows. <\/p>\n

Issue 2<\/h6>\n

When you configure the CPU limit on a virtual machine, the virtual machine is allocated less resources than the limit that you configured. For example, if you set the CPU limit on a virtual machine to 20 percent of CPU resources on the computer, the virtual machine is allocated less than 20 percent of CPU resources. <\/p>\n

 <\/p>\n

Cause<\/u><\/strong><\/p>\n

Cause of Issue 1<\/h6>\n

This issue occurs because the timer clock interrupts are not sent to the virtual machine in time. Therefore, the virtual machine assumes that a hardware error occurred. <\/p>\n

Cause of Issue 2<\/h6>\n

This issue occurs because the hypervisor throttles the resources that are provided to the virtual machine.<\/p>\n<\/blockquote>\n

A supported hotfix is available from Microsoft. <\/p>\n

Technorati Tags: Windows Server 2012<\/a>,Windows 8<\/a>,Hyper-V<\/a>,Hyper-V Server<\/a>,Virtualisation<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"

Microsoft has released a KB article for when CPU resources are not allocated correctly for a virtual machine running on Windows 8 Client Hyper-V or Windows Server 2012 Hyper-V. This article is related to unexpected behaviour with the virtual processor resource control settings of a VM in Hyper-V.  Most people never touch these settings, and … Continue reading “KB2885465 – CPU Not Allocated Correctly VMs On Win8 Or WS2012 Hyper-V”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","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":[181,67,195,109,118],"class_list":["post-15550","post","type-post","status-publish","format-standard","hentry","category-hyper-v","tag-hyper-v","tag-hyper-v-server","tag-virtualisation","tag-windows-8","tag-windows-server-2012"],"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