Welcome to another of our series of “VMware or Microsoft?” articles. Hyper-V 3 which is built into both the Free Hyper-V Server 2012 and Windows Server 2012 (Standard and Datacenter) which you can evaluate for free (free ISO, free VHD), has some really awesome capabilities. You can read more about Hyper-V in the overview of the Server Virtualization Series: Hyper-V Basics. In this article, we are going to drill down into what I think is one of the best features of Server Virtualization. A feature Microsoft calls Dynamic Memory. As part of the discussion, we will cover memory virtualization on other platforms so you get a solid understanding of the very, very important concept of “Virtual Memory”. In particular we will look at how it stacks up with VMware’s virtual memory solution called Memory Overcommit. We will sprinkle in Step-By-Step & How-To’s so you can do it yourself. Dynamic memory has significantly changed the world of server virtualization. It is a feature, you NEED to understand and leverage.
Dynamic Memory is an optional feature that you can turn on and off with a simple checkbox. With Dynamic Memory you can attain higher consolidation numbers with improved reliability for restart operations. This can lead to lower costs, especially in environments that have many idle or low-load virtual machines, such as pooled VDI environments or web servers. Dynamic Memory run-time configuration changes can reduce downtime and provide increased agility to respond to requirement changes. For more on runtime configuration changes see Kevin Remde’s blog post You Want to Hot-Add What?! : 20+ Days of Server Virtualization (Part 2 of 20). If you have not yet installed Hyper-V you can follow the Hands-On-Lab guide at http://itproguru.com/hol it is the “Install/Enable and Configure Hyper-V Getting Started” lab.
Dynamic memory was introduced in Windows Server 2008 R2 with SP1. It gave the Hyper-V hypervisor the capability to dynamically adjust the amount of memory assigned to a machine based on memory demand. The reason we would want to do this is simple. This gives us: Higher consolidation numbers, Improved reliability of Hyper‑V operations, and Ability to increase maximum memory configuration with minimal downtime. If we can put only the amount of memory a machine needs in the box, we can fit more machines on a host.
How’s that? When you deploy a server ... Read More
Not everyone grasps the difference in 'virtual' vs. 'statically-assigned' memory. This is a wonderful article. Thanks.
I actually posted that last comment, but Technet, since last night, has been having odd problems, logging us out and very slow and NOT acknowledging posts, etc.
So anyway, Not everyone grasps the difference in 'virtual' vs. 'statically-assigned' memory. This is a wonderful article. Thanks.