As a provider that leverages Microsoft\u2019s Hyper-v technology to deliver cost effective high performance cloud resources to our customers, I\u2019m excited to see where Microsoft is taking vNext. Currently, virtual machines (VM) in the cloud act very similar to their physical counterparts. If you wish to upgrade processors or add memory to a server, you power down the server, swap out or add the new resources, then power the server back on.<\/p>\n
Hyper-V currently supports dynamic memory allocation in which you can specify start-up, minimum and maximum memory values. The VM will boot with the start-up value, then automatically adjust the allocation within the constrains established, allwhile maintaining a buffer of free memory that is also user definable in the form of a percentage. Dynamic memory allocation can certanly help some organizations oversubscribe their current infrastructure, allowing them to\u00a0pack more VM\u2019s per physical server, so long as they monitor the underlying host\u2019s memory usage or leverage some type of host optimization system (ie. Virtual Machine Manager) to shuffle VM\u2019s around when memory becomes a constraint on physical hosts.<\/p>\n
For a few reasons, we don\u2019t leverage dynamic memory in our private cloud service offering. First, we found dynamic memory will sometimes introduce erratic performance to the virtual machine, so we’ve always reserve this feature\u00a0primarily for\u00a0our lab and internal environments. When we do leverage dynamic memory, it\u2019s primarily used\u00a0for services such as domain controllers where it\u2019s handy to have a few gigabytes of memory to interact with when you need it, but when\u00a0no one logged in, it may only need a quarter of that to do it’s job successfully. We never give a demanding server such as SQL dynamic memory, although we wish we could though. The other dislike we have with the current iteration of dynamic memory has to do with the way\u00a0Microsoft\u2019s memory ballooning\u00a0gets represented in the task manager for windows and top for linux. It inaccurately portrays the virtual machine as consuming all available memory, which has a tenancy to confuse our users and makes initial troubleshooting processes\u00a0more difficult.<\/p>\n
In the next iteration of Windows Server\/Hyper-V, hot memory re-sizing will be introduced. This will allow static amounts of memory to be added or removed on the fly without virtual machine downtime. The stipulations imposed at this time are the guest OS needs to be a vNext OS and you cannot remove memory that\u2019s being used. The latter doesn’t concern\u00a0me much as I wouldn’t want to impose memory swapping on a VM by taking away memory in use, but hopefully in time Microsoft will be able to extend the host memory re-sizing technology to at least Windows Server 2012 R2 as it will save a lot of downtime for applications as they grow. With a little luck, this might have an impact on\u00a0Hyper-V\u2019s dynamic memory problems at the same time, yielding even more avenues for delivering cost effective and highly reliable resources to consumers.<\/p>\n","protected":false},"excerpt":{"rendered":"
As a provider that leverages Microsoft\u2019s Hyper-v technology to deliver cost effective high performance cloud resources to our customers, I\u2019m excited to see where Microsoft is taking vNext. Currently, virtual machines (VM) in the cloud act very similar to their physical counterparts. If you wish to upgrade processors or add memory to a server, you<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[5],"tags":[],"_links":{"self":[{"href":"https:\/\/www.enseva.com\/index.php?rest_route=\/wp\/v2\/posts\/1421"}],"collection":[{"href":"https:\/\/www.enseva.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.enseva.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.enseva.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.enseva.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1421"}],"version-history":[{"count":6,"href":"https:\/\/www.enseva.com\/index.php?rest_route=\/wp\/v2\/posts\/1421\/revisions"}],"predecessor-version":[{"id":1435,"href":"https:\/\/www.enseva.com\/index.php?rest_route=\/wp\/v2\/posts\/1421\/revisions\/1435"}],"wp:attachment":[{"href":"https:\/\/www.enseva.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1421"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.enseva.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1421"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.enseva.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1421"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}