Sharing of thoughts and information is what blogging is all about. This way we can learn from each other. Post A Comment!These postings are provided "AS IS" with no warranties, and confers no rights. You assume all risk for your use.
Anthony Bartolo Twitter | LinkedIn
Pierre Roman Twitter | LinkedIn
In November I posted the first of several post that covered building a lab at home. Then I followed up with Windows Server 2012 IT Camp – Lab #1 .
This is third one in this series and it will cover the following:
Importing a virtual machine from one physical host to another can expose file incompatibilities and other unforeseen complications. Administrators often think of a virtual machine as a single, stand-alone entity that they can move around to address their operational needs. In reality, a virtual machine consists of several parts:
Each virtual machine and each snapshot that is associated with it use unique identifiers. Additionally, virtual machines store and use some host-specific information, such as the path that identifies the location for virtual hard disk files. When Hyper‑V starts a virtual machine, it undergoes a series of validation checks before being started. Problems such as hardware differences that might exist when a virtual machine is imported to another host can cause these validation checks to fail. That, in turn, prevents the virtual machine from starting.
Windows Server 2012 includes an Import wizard that helps you quickly and reliably import virtual machines from one server to another.
The Import Wizard for virtualization:
The flowchart shows the Import Wizard process.
When you import a virtual machine, the wizard does the following:
The new Import Wizard is a simpler, better way to import or copy virtual machines. The wizard detects and fixes potential problems, such as hardware or file differences that might exist when a virtual machine is imported to another host.
As an added safety feature, the wizard creates a temporary copy of a virtual machine configuration file in case an unexpected restart occurs on the host, such as from a power outage. The Windows PowerShell cmdlets for importing virtual machines let you automate the process.
In Windows Server 2012, Fast-growing organizations whose workloads are rapidly expanding often need to add more virtual machines to their host processors. These organizations want to optimize the number of virtual machines that they can place on a host server to minimize the number of expensive host servers that they need. With the Hyper-V Dynamic Memory improvements in Windows Server 2012 , IT administrators can now allocate virtual machine memory resources more efficiently and dramatically increase virtual machine consolidation ratios.
Dynamic Memory improvements in Windows Server 2012 include support for higher virtual machine consolidation with minimum memory and Hyper-V smart paging.
Minimum memory lets Hyper‑V reclaim the unused memory from virtual machines. This can result in increased virtual machine consolidation numbers, especially in VDI environments.
Although minimum memory increases virtual machine consolidation numbers, it also brings a challenge. If a virtual machine has a smaller amount of memory than its startup memory and it’s restarted, Hyper‑V needs additional memory to restart the machine. Due to host memory pressure or the states of the virtual machines, Hyper‑V may not always have additional memory available. This can cause sporadic virtual machine restart failures in customer environments. In Windows Server 2012, Hyper-V smart paging is used to bridge the memory gap between minimum and startup memory and allow virtual machines to restart reliably.
Hyper-V smart paging allows virtual machines to start reliably when the minimum memory setting has indirectly led to an insufficient amount of available physical memory during restart.
As in the earlier version of Dynamic Memory, you can configure minimum memory for your virtual machines and Hyper‑V continues to help ensure that this amount is assigned to running virtual machines. To provide a reliable restart experience for the virtual machines configured with less minimum memory than startup memory, Hyper‑V Windows Server 2012 uses Hyper-V smart paging.
Hyper-V smart paging is a memory management technique that uses disk resources as additional, temporary memory when more memory is required to restart a virtual machine. This approach has advantages and drawbacks. It provides a reliable way to keep the virtual machines running when no physical memory is available. However, it can degrade virtual machine performance because disk access speeds are much slower than memory access speeds.
To minimize the performance impact of Hyper-V smart paging, Hyper‑V uses it only when all of the following occur:
Hyper-V smart paging isn’t used when:
Hyper‑V continues to rely on internal guest paging when host memory is oversubscribed because it’s more effective than Hyper-V smart paging. With internal guest paging, the paging operation inside virtual machines is performed by Windows Memory Manager. Windows Memory Manager has more information than the Hyper‑V host about memory usage within the virtual machine, which means it can provide Hyper‑V with better information to use when choosing the memory to be paged. Because of this, internal guest paging incurs less overhead to the system when compared to Hyper-V smart paging.
To further reduce the impact of Hyper-V smart paging, after a virtual machine completes the startup process, Hyper‑V removes memory from the virtual machine, coordinating with Dynamic Memory components inside the guest (a process sometimes referred to as “ballooning”), so that the virtual machine stops using Hyper-V smart paging. With this technique, the use of Hyper-V smart paging is temporary and is not expected to be longer than 10 minutes.
Windows Server 2012 Hyper-V enables you to make the following configuration changes to Dynamic Memory when the virtual machine is running:
After Lab #1 We have our 2 physical machines and 2 virtual Domain controllers (one on each physical hosts)
VMhost10a and VMhost10b. We have them configured as follows:
ITCAMP-DC1 and ITCAMP-DC2. We have them configured as follows:
In this lab we will get our hands on a couple more machines that we will build and use in our scenarios.
Using the VHD downloaded here (http://technet.microsoft.com/en-ca/evalcenter/hh670538.aspx) after extracting it to a temporary location, I copied it to the location I want my ITCAMP-SMB machine to be located and renamed it to ITCAMP-SMB. Once that’s done I created a new Virtual machine on VMHost10A with the following settings:
Once the machine is created, open the settings for ITCAMP-SMB and under the “SCSI Controller” add 4 disks as shown in the exhibit below:
Once it’s started, there are a few things to do for setup before we can continue with the labs.
That one is a little easier. Since System Center 2012 Service Pack 1 is not out yet, you still have to download a pre-baked machine to be used as a System Center 2012 Virtual Machine manager. you can get the SCVMM machine here (http://aka.ms/SCVMM2012SP1)
Once you’ve downloaded and expanded it on VMHost10B just follow the directions included with the virtual machine.
Here is what we have at the end of the build process:
Lab #2 will consist in the following:
Here is the 7 minutes video on this lab.
If you have other scenarios you would like me to explore and post please leave me a comment.
As always, the easiest way to learn is to download the evaluation and start getting your hands dirty.
you can find the evaluation download here. ( http://aka.ms/ws2012eval)
Pierre Roman, MCITP, ITIL | IT Pro Advisor Twitter | Facebook | LinkedIn