{"id":13229,"date":"2012-08-07T09:00:00","date_gmt":"2012-08-07T08:00:00","guid":{"rendered":"https:\/\/aidanfinn.com\/?p=13229"},"modified":"2012-08-07T09:00:00","modified_gmt":"2012-08-07T08:00:00","slug":"ws2012-hyper-v-choosing-between-storage-controllers","status":"publish","type":"post","link":"https:\/\/aidanfinn.com\/?p=13229","title":{"rendered":"WS2012 Hyper-V \u2013 Choosing Between Storage Controllers"},"content":{"rendered":"<p><em>The <\/em><a href=\"http:\/\/download.microsoft.com\/download\/0\/0\/B\/00BE76AF-D340-4759-8ECD-C80BC53B6231\/performance-tuning-guidelines-windows-server-2012.docx\"><em>Performance Tuning Guidelines for Windows Server 2012<\/em><\/a><em> document is available and I\u2019m reviewing and commenting on notable text in it.<\/em><\/p>\n<p>There are 3 types of storage controller:<\/p>\n<ul>\n<li>IDE<\/li>\n<li>SCSI<\/li>\n<li>Virtual HBA<\/li>\n<\/ul>\n<p><strong><u>IDE<\/u><\/strong><\/p>\n<p>There are 2 IDE controllers (0 and 1), with each one having 2 channels.&#160; In other words, you can have 4 devices attached to IDE.&#160; Two quick notes:<\/p>\n<ul>\n<li>Your boot drive must be attached to IDE.&#160; You have no choice in this.&#160; Before the VMware fanboy shite starts, this is a software controller and has no relevance to the hardware.&#160; Your hosts don\u2019t need IDE controllers.&#160; It is a simulated virtual device and performs just as well as SCSI, as Ben Armstrong <a href=\"http:\/\/blogs.msdn.com\/b\/virtual_pc_guy\/archive\/2009\/12\/01\/why-hyper-v-cannot-boot-off-of-scsi-disks-and-why-you-should-not-care.aspx\" target=\"_blank\">pointed out<\/a> years ago.<\/li>\n<li>The virtual CD\/DVD drive will be mounted to the IDE controllers, usually IDE 1.&#160; Microsoft states that you can save host resources by removing this device if it is not used.&#160; Be careful, you need it to do the usual manual Integration Services upgrade, install s\/w from ISO (as you would in a cloud via the VMM library).&#160; <\/li>\n<\/ul>\n<p>Adding or removing devices to IDE requires the VM to be powered down.<\/p>\n<p><strong><u>SCSI<\/u><\/strong><\/p>\n<p>The virtual SCSI controller has nothing to do with hardware either.&#160; It is a simulated virtual device.&#160; A benefit is that it allows hot add of storage to a running VM.&#160; WS2012 SCSI attached VHDX enables unmap to save physical disk space.&#160; A single SCSI controller allows up to 64 attached disks.&#160; You can have up to 4 SCSI controllers.&#160; That\u2019s 256 SCSI attached disks. That\u2019s a lot of storage if you use 64 TB VHDX!<\/p>\n<p><strong><u>Virtual HBA<\/u><\/strong><\/p>\n<p>You can virtualise your host\u2019s physical HBA ports to create <a href=\"https:\/\/aidanfinn.com\/?p=12115\" target=\"_blank\">virtual HBAs<\/a> in the VMs on that host.&#160; This allows your VMs to have their own WWNs and directly connect to the SAN, using NPIV (required).&#160; If your SAN vendor supports it, you can run their DSM\/MPIO to use multiple virtual HBAs in a VM.&#160; This gives greater storage IO performance and provides fault tolerance if you design the virtual SANs correctly.&#160; <\/p>\n<p>Microsoft says you can do this for large LUNs.&#160; I strongly urge you to use VHDX for this if you need up to 64 TB in your large LUN:<\/p>\n<ul>\n<li>More flexible\/mobile (storage migration), unlike LUNs that are physically bound to the SAN<\/li>\n<li>Can be backed up at the host\/storage level, unlike physical LUNs that can only be backed up by an agent in the VM<\/li>\n<\/ul>\n<p>A really good reason is virtual guest clusters, where you need some shared storage between the (up to 64) nodes in the guest cluster.<\/p>\n<div style=\"padding-bottom: 0px; margin: 0px; padding-left: 0px; padding-right: 0px; display: inline; float: none; padding-top: 0px\" id=\"scid:0767317B-992E-4b12-91E0-4F059A8CECA8:13c1a9bd-c237-491e-b649-072f32810118\" class=\"wlWriterEditableSmartContent\">Technorati Tags: <a href=\"http:\/\/technorati.com\/tags\/Windows+Server+2012\" rel=\"tag\">Windows Server 2012<\/a>,<a href=\"http:\/\/technorati.com\/tags\/Hyper-V\" rel=\"tag\">Hyper-V<\/a>,<a href=\"http:\/\/technorati.com\/tags\/Virtualisation\" rel=\"tag\">Virtualisation<\/a>,<a href=\"http:\/\/technorati.com\/tags\/Performance\" rel=\"tag\">Performance<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"<p>The Performance Tuning Guidelines for Windows Server 2012 document is available and I\u2019m reviewing and commenting on notable text in it. There are 3 types of storage controller: IDE SCSI Virtual HBA IDE There are 2 IDE controllers (0 and 1), with each one having 2 channels.&#160; In other words, you can have 4 devices &hellip; <a href=\"https:\/\/aidanfinn.com\/?p=13229\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;WS2012 Hyper-V \u2013 Choosing Between Storage Controllers&#8221;<\/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,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[20],"tags":[181,86,195,118],"class_list":["post-13229","post","type-post","status-publish","format-standard","hentry","category-hyper-v","tag-hyper-v","tag-performance","tag-virtualisation","tag-windows-server-2012"],"aioseo_notices":[],"jetpack_featured_media_url":"","amp_enabled":true,"_links":{"self":[{"href":"https:\/\/aidanfinn.com\/index.php?rest_route=\/wp\/v2\/posts\/13229","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aidanfinn.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aidanfinn.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aidanfinn.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aidanfinn.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=13229"}],"version-history":[{"count":0,"href":"https:\/\/aidanfinn.com\/index.php?rest_route=\/wp\/v2\/posts\/13229\/revisions"}],"wp:attachment":[{"href":"https:\/\/aidanfinn.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=13229"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aidanfinn.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=13229"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aidanfinn.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=13229"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}