Zeros & Ones

Michael Michael has posted a great blog that outlines exactly how to restore the metadata through the use of powershell scripts.

http://blogs.technet.com/b/m2/archive/2010/04/16/saving-and-re-applying-the-virtual-machine-metadata-in-vmm.aspx

The saved metadata can be applied later on in the event that you add and remove the host from VMM management. A scenario where this issue comes up is when something goes wrong with your host in VMM and you need to remove it from management and re-add it to VMM (the host can also be a cluster). Typically in a situation like this you will loose all the metadata associated with your virtual machines. Such metadata includes the custom properties, descriptions, tags, owner, cost center, etc. If it is 1 or 2 VMs, its not a big deal to add them back, but when you are talking about a cluster with 200 VMs it is quite an effort.

Error (2912)
An internal error has occurred trying to contact an agent on the vmmserver.contoso.com server.

Recommended Action
Ensure the agent is installed and running. Ensure the WS-Management service is installed and running, then restart the agent.

Cause:

During the ‘Make operating system virtualizable’ step, files are copied from the destination host (the server that will host the virtualized system) to the SCVMM Server. This BITS operation fails due to a certificate problem as indicated by the error 0x80072F0C (ERROR_INTERNET_CLIENT_AUTH_CERT_NEEDED).

Resolution:

To resolve this issue, remove the managed host from the SCVMM server and also delete any residual certificates from the host on the VMM server, then re-add the host:

1. On the SCVMM server, remove the managed host from the console. The steps on how to remove a managed host are outlined in the following TechNet article:

http://technet.microsoft.com/en-us/library/cc956121.aspx (http://technet.microsoft.com/en-us/library/cc956121.aspx)

2. Now we need to locate and delete any certificates for the Host computer.

3. Open the Certificate console on the SCVMM server.

a. Open a new mmc and add the certificates snap-in.
b. Select the option of ‘computer account’ and ‘local computer’.
c. Select Finish and Ok to load the snap-in.

4. The certificates for the Host computer can be in any of the following locations.

a. Personal Certificates.
b. Trusted People (if the host is W2K8 or W2K8 R2).
c. Trusted Root Authorities (If the host is W2K3).

5. In each store, expand the Friendly Name field and locate the certificate[s] for the Host server that have a Friendly Name starting with ‘SCVMM_CERTIFICATE_KEY_CONTAINER’ followed by either the FQDN / IP address / NetBIOS name of the Host server and delete them.

6. Re-add the host in SCVMM which recreates the certificates as needed.

More Information:

SCVMM uses BITS to transfer payload between SCVMM managed computers. These data transfers are encrypted by using a self-signed certificate generated at the time a host machine is added to SCVMM. If these certificates are missing or corrupted from the SCVMM server or managed computers, the payload deployment job can fail. Deleting the certificates and re-adding the host will cause the certificates to be regenerated.

For the latest information on this issue see the following Knowledge Base article:

KB2385280 – P2V fails with Error 2912 0x80072F0C with System Center Virtual Machine Manager 2008 or System Center Virtual Machine Manager 2008 R2

J.C. Hornbeck | System Center Knowledge Engineer

I think this forum post is deserve sharing

Situation : Windows Server 2008 R2 with latest patches (SP1 beta is NOT installed)

Windows Server 2008 SP2 with latest patches

CreationTimes for snapshots of virtual machines that were originally created on the same server are correct.

CreationTimes for snapshots of virtual machines that have been exported/imported between 2008 SP2 virtual hosts are correct.

But CreationsTimes for snapshots of virtuals that have been exported and imported onto 2008 R2 virtual hosts are incorrect.

Cause of the issue: As per Vincent Hu Hyper-V product team is aware of it.

For CreationTime property we rely on configuration file creation time until someone calls SetCreationTime() on configuration. Once SetCreationTime is called, we add a property, "creation_time", to config xml file and subsequent GetCreationTime() call will get its value from this property. While taking snapshot we do not call SetCreationTime() and hence, after import, the newly created snapshots also get incorrect creation time.

Here is the workaround: Removing the creation_time data from the vm's configuration file.

So this is an interesting topic… Server virtualization technologies have become so simple and efficient for most organizations.. Using the advanced technologies to provide high availability like ( Hyper-V Live and Quick migration or VMWare  VMotion ) had make things easier to keep your VMs HA and retain your SLA. Although that using Clustering technologies have some recommendations based on the used technology.. MS Exchange team already published recommendations for running Exchange in the Virtualization Environments.

Part of it was “We recommend using the built-in Exchange Server high availability solutions for virtualized Exchange servers instead of hypervisor-provided clustering or portability solutions (such as Hyper-V’s quick migration feature). The features found in Exchange Server (in particular, cluster continuous replication (CCR)) provide greater benefits than those found in hypervisor solutions that move virtual machines between physical root machines.

We do not recommend using hypervisor-based virtual machine migration (such as Hyper-V’s quick migration) for virtualized Exchange servers. In a virtual machine migration configuration, an unscheduled outage can result in data loss. In a CCR environment, this type of data loss is largely mitigated by a feature called transport dumpster. The transport dumpster takes advantage of the redundancy in the environment to reclaim some of the data affected by the failover.”

So what about the rest of technologies like File Server clusters or DHCP. What if you want to implement DHCP and File Server Clusters ( Guest Clustering ) over Hyper-V hosts Cluster ( Cluster over Cluster ) ?

is that supported ? Do we have any limitations or well known problem with that ?

It takes some search and some support from Microsoft and hereunder the answer

This would be a combination of guest clustering and host clustering. This scenario would be working as long as you pass the cluster validation report.

Here are some tips for combing guest and host clustering for your information.
• Affinity – It is recommended that the nodes of a guest cluster should reside on different hosts to achieve the highest levels of availability.  If a host were to crash, having VM’s associated with the same guest cluster distributed across multiple hosts will enable applications to recover faster.  To accomplish this, configure the cluster group property AntiAffinityClassName.  The host cluster will attempt to keep VM’s with a consistent string value (such as the VM name) off the same host.  See this KB for additional details:  http://support.microsoft.com/kb/296799
• Heartbeat Thresholds – It may be necessary to increase the cluster heartbeat thresholds of a guest cluster when a mobile guest VM node is being moved to a new host, through a process such as live migration.  During the migration of the VM it will be temporarily unavailable for a brief period of time which cluster health detection may detect, increasing the thresholds will mitigate clustering assuming the node is down and incorrectly taking recovery actions.  This can be accomplished by increasing the SameSubnetThreshold and SameSubnetDelay cluster common properties.  See this document for additional details:  http://technet.microsoft.com/en-us/library/dd197562(WS.10).aspx

So you can provide more redundancy for your VMs by providing a combination of host and guest clustering and get rid of your down time.

Some useful links

Hyper-V Guest Clustering Step-by-Step Guide

http://blogs.technet.com/b/mghazai/archive/2009/12/12/hyper-v-guest-clustering-step-by-step-guide.aspx

Failover Clustering & NLB Documents and Resources

http://blogs.msdn.com/b/clustering/archive/2009/08/21/9878286.aspx

Hyper-V: Using Hyper-V and Failover Clustering

http://technet.microsoft.com/en-us/library/cc732181(WS.10).aspx

Hyper-V team just published a new KB article called “Configuring Certificates for Virtual Machine Connection“ that talks about the way Hyper-V uses certificates and how to set it up. They also explain why we need them, something that might help new users and customers. This article provides information to folks who need to set this up and to folks who wanted to know how to work around wildcard certs.

It was put together by a member of our Test team, Krishna, at the request of our product support folks and now it’s here for you.

Enjoy it

A while ago I wrote about virtualization of Office Communication Server 2007 R2, OCS 2007 R2 had a limited supportability for virtualization” Only the Presence, IM (including remote access, federation, and PIC) and Group Chat workloads”.

The next release of Office Communications Server and Communicator together with Exchange 2010 is currently referred to as UC “Wave 14″ (code-name). The latest publicly available release date is in “late 2010”.

With Wave 14, OCS 2010 will support virtualization .. Yes it will

What’s supported?

• Virtualization of specific Communications Server roles
• SQL, Exchange, and AD virtualization where appropriate
• Hyper-V R2 (not R1)
• Client virtualization (except Audio / video) – use IP phone

“client virtualization technologies such as Citrix is supported for IM and meetings but audio and video is NOT supported .  Microsoft’s recommendations is to use an IP phone if virtualized desktops are used.”

What’s not supported?

• Branch office / gateway only / mediation server + gateway
• Standard edition servers (already a single box)
• Live Migration of Communications Server VMs

We are really excited to announce the availability of the Hyper-V Linux Integration Services for Linux Version 2.1. This release marks yet another milestone in providing a comprehensive virtualization platform to our customers. Customers who have a heterogeneous operating system environment desire their virtualization platform to provide support for all operating systems that they have in their datacenters. We have supported Linux as a guest operating system on our virtualization platform from the days of Virtual Server and continue to enhance our support in that regard.

The following features are included in the 2.1 release:

Driver support for synthetic devices: Linux Integration Services supports the synthetic network controller and the synthetic storage controller that were developed specifically for Hyper-V.

Fastpath Boot Support for Hyper-V: Boot devices take advantage of the block Virtualization Service Client (VSC) to provide enhanced performance.

Timesync: The clock inside the virtual machine will remain synchronized with the clock on the host.

Integrated Shutdown: Virtual machines running Linux can be gracefully shut down from either Hyper-V Manager or System Center Virtual Machine Manager.

Symmetric Multi-Processing (SMP) Support: Supported Linux distributions can use up to 4 virtual processors (VP) per virtual machine.

Heartbeat: Allows the host to detect whether the guest is running and responsive.

Pluggable Time Source: A pluggable clock source module is included to provide a more accurate time source to the guest.

This version of the integration services for Hyper-V supports Novell SUSE Linux Enterprise Server 10 SP3, SUSE Linux Enterprise Server 11, and Red Hat Enterprise Linux 5.2 / 5.3 / 5.4 / 5.5.

Customers can obtain the Linux IC’s via the Microsoft Download Center at this link: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=eee39325-898b-4522-9b4c-f4b5b9b64551

While the Microsoft Sysinternals tools are incredibly powerful and useful, the one feature they lack is the ability to check for new versions. Currently, you have to periodically check the Sysinternals site and compare versions between your system and the most recent official release in order to stay up to date.

As a better solution, Jason Faulkner have created a batch script which will automatically update the Sysinternals tools you have on your system. All you have to do is put the batch script file into the folder where your Sysinternals tools are located and the script does the rest, no configuration is needed.

Check it there

What is Dynamic Memory?

Dynamic memory overview

Dynamic memory allows you to configure a virtual machine so that the amount of memory assigned to the virtual machine is adjusted while the virtual machine is running, in reaction to the amount of memory that is actually being used by the virtual machine.  This allows you to run a higher number of virtual machines on a given physical computer.  It also ensures that memory is always distributed optimally between running virtual machines.

Before enabling dynamic memory in a virtual machine you need to ensure that the latest version of integration services is installed in the virtual machine.You can then enable dynamic memory for a virtual machine using the memory settings under the virtual machine settings.  Once dynamic memory is enabled there are four parameters that you can configure:

• Initial memory.
  This is the amount of memory that is required to start the virtual machine.  This value needs to be high enough to allow the guest operating system to boot, but should be as low as possible to allow for optimal performance with dynamic memory.The virtual machine will never be assigned less memory than the initial memory value.
• Maximum memory.
  The virtual machine will not be allowed to use more memory than is specified by this value.  This value can be configured anywhere from the initial memory value up to 64GB.
• Memory buffer.
  The memory buffer value indicates how much memory is assigned to the virtual machine when compared to the amount of memory actually needed by the applications and services running inside the virtual machine.
  The memory buffer will not be maintained if there is not enough physical memory available in the computer to give every virtual machine its requested memory buffer.
• Memory priority.
  The memory priority value reflects how memory will be distributed amongst virtual machines if there is not enough physical memory available in the computer to give every virtual machine its requested amount of memory.
  Higher priority virtual machines will be given more memory when compared to lower priority virtual machines with similar settings.

Supported guest operating systems

Dynamic memory is supported for the following guest operating systems:

• Windows Server 2008 R2 Enterprise Edition (32-bit and 64-bit)
• Windows Server 2008 R2 Datacenter Edition (32-bit and 64-bit)
• Windows 7 Ultimate Edition (32-bit and 64-bit)
• Windows 7 Enterprise Edition (32-bit and 64-bit)
• Windows Server 2008 Enterprise Edition (32-bit and 64-bit)
• Windows Server 2008 Datacenter Edition (32-bit and 64-bit)
• Windows Vista Ultimate Edition (32-bit and 64-bit)
• Windows Vista Enterprise Edition (32-bit and 64-bit)
• Windows Server 2003 R2 Enterprise Edition (32-bit and 64-bit)
• Windows Server 2003 R2 Datacenter Edition (32-bit and 64-bit)
• Windows Server 2003 Enterprise Edition (32-bit and 64-bit)
• Windows Server 2003 Datacenter Edition (32-bit and 64-bit)

If you enable dynamic memory for a virtual machine that is running an operating system that is not on this list, the guest operating system will only be able to access the initial memory.

For each supported operating system you should follow the published required and recommended memory values prior to installing the latest integration services and enabling dynamic memory.  Once dynamic memory is enabled you can use a lower initial value in order to get the best performance out of dynamic memory.  The maximum memory value should always be greater than the required memory for the operating system that is running in the virtual machine.

Tuning dynamic memory for best performance

If you enable dynamic memory on a virtual machine and are not satisfied with the performance that you receive from the virtual machine, there are multiple configuration changes that you can make to potentially improve performance:

• Increase the size of the page file inside the guest operating system.
  A larger page file inside the virtual machine allows larger amounts of memory to be added to the running virtual machine if it is needed suddenly.  It also lets the virtual machine run better when the availability of physical memory is limited.
• Increase the memory buffer configured for the virtual machine.
  Increasing the memory buffer will result in more memory being assigned to the virtual machine when compared to the amount of memory actually needed by the applications and services running inside the virtual machine.  This extra memory can then be used for file caching purposes, and may help with the performance of IO intensive applications and services.
• Increase the initial memory for the virtual machine.
  Some applications assign fixed amounts of memory based on the amount of memory available when the application first starts.  These applications will perform better with higher values for the initial memory.
  Alternatively, if you are seeing poor performance due to too much memory being removed from the virtual machine, increasing the initial memory value can also alleviate this problem.
  It should be noted that by increasing the initial memory value, the overall flexibility and effectiveness of dynamic memory is reduced.

Increase the virtual machine memory priority.
Increasing the virtual machine memory priority will ensure that available physical memory is assigned to this virtual machine before being

Source: Windows Server 2008 R2 and Windows 7 Service Pack 1 Test Focus Guide

So most of use already knows that VMM 2008 R2 required Windows 2003 Domain level for the installation and I already blogged about some error that you may face if VMM is connected and authenticated by windows 2000 domain controller in the installation phase.

But it was a new question when one asked me “Why Windows 2003 Domain Level?”

Kerberos authentication is a prerequisite for VMM. To configure your environment to allow users in one Active Directory Domain Services (AD DS) domain to access VMM resources in another domain, you can either ensure that both domains are in the same forest or configure a forest-level trust relationship and use Kerberos authentication. To set up a forest-level trust relationship, both domains must be in Windows Server 2003 forest mode. Windows 2000 Server does not support forest-level trusts.

Windows Server 2003 and Windows 2000 Server environments that contain complex group structures can encounter problems with an access token limitation during authentication.

The Kerberos Access Token in Windows 2000 native mode environment had many limitations and the resolution is just simply to raise domain function level to Windows 2003.

Check MS Addressing Problems Due to Access Token Limitation

http://download.microsoft.com/download/8/f/3/8f36dfe4-47d0-4775-ad5a-5614384921aa/AccessTokenLimitation.doc

This is a very important question… When SCVMM will support Dynamic Memory feature introduced in Windows 2008 R2 SP1 Hyper-V server?

There is less public information about the new features that integrated with Windows 2008 R2 SP1 so far, So I had to check with MS private newsgroup.

Brandon for newsgroup came back with this answer ” I had consulted our SCVMM product team and the answer I got is there will be a “feature pack” for SCVMM 2008 R2 that will add-in the capability to manage the new Dynamic Memory feature coming in Windows Server 2008 R2 SP1.  Our product team will try to RTM SCVMM package very shortly after the RMT date of Windows 2008 R2 SP1. There will be no SCVMM support for pre-release builds of Windows 08 R2 SP1 until the RC milestone. “

Service Pack 1 for Windows 7 and Windows Server 2008 R2 will be released “within the first half of calendar year 2011,” Microsoft announced this week.

The service pack is currently available as a beta for test purposes, having been released earlier this month. However, this week, Microsoft published a FAQ on the SP1 beta, which disclosed the approximate product release date for the service pack, perhaps for the first time.

So nothing expected before the first half of calendar year 2011.