Category Archives: High Availability

Exchange 2010 SP1 DAG & Unified Messaging Now Supports Host Based High Availability & Live Migration!

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Well due to rather nice virtualization support for Lync and the fact that Denali (SQL Server vNext) does support DAG like functionality with Live Migration and host based clustering, it was about time for Exchange 2010 to catch up. And when we read the white paper  Best Practices for Virtualizing Exchange Server 2010 with Windows Server® 2008 R2 Hyper V™ that moment has finally arrived. I have to thank Michel de Rooij at  for bringing this to our attention http://eightwone.com/2011/05/14/exchange-2010-sp1-live-migration-supported/. So now we have the best features in virtualization at our disposal and that simply rocks. We read:

“Exchange server virtual machines, including Exchange Mailbox virtual machines that are part of a Database Availability Group (DAG), can be combined with host-based failover clustering and migration technology as long as the virtual machines are configured such that they will not save and restore state on disk when moved or taken offline. All failover activity must result in a cold start when the virtual machine is activated on the target node. All planned migration must either result in shut down and a cold start or an online migration that utilizes a technology such as Hyper-V live migration.”

“Microsoft Exchange Server 2010 SP1 supports virtualization of the Unified Messaging role when it is installed on the 64-bit edition of Windows Server 2008 R2. Unified Messaging must be the only Exchange role in the virtual machine. Other Exchange roles (Client Access, Edge Transport, Hub Transport, Mailbox) are not supported on the same virtual machine as Unified Messaging. The virtualized machine configuration running Unified Messaging must have at least 4 CPU cores, and at least 16 GB of memory.”

And it is NOT ONLY for Hyper-V, look at the Exchange Team blog here “The updated support guidance applies to any hardware virtualization vendor participating in the Windows Server Virtualization Validation Program (SVVP).’” Nice!

Anyone who’s at TechEd USA 2011 in Atlanta should attend EXL306 for more details. Huge requirements yes, but the same goes for physical servers. That’s how they get the performance gains needed, it’s done by lowering IO by using large amounts of RAM.

Think about the above statement, we now have support for host clustering with live migration, possibly together with technology like for example Melio (SanBolic) on the software side or Live Volume (Compellent) on the storage side to protect against SAN Failure (local or remote) and combined with DAG high availability for the databases in Exchange 2010 (which can be multi site) this becomes a very resilient package. So to come back to my other post on a brighter future for public folders, if they can sort out this red headed stepchild of the Exchange portfolio they have covered all their bases and have a great platform with the option of making it better, easier and cheaper to implement, operate & use. No one will argue with that.

I know some people will say all this is overkill, to complex, to much or to expensive. I call it having options. When the S* hits the fan and you’re “in the fight of your life” wading your way through one or multiple IT disasters to keep that mail flow up an running it is good to have multiple options. Options mean you can get the job done using creativity and tools. If you have only one tool and one option Murphy will catch up with you. Actually this is one of my most heard shout outs to the team “give me options” when problems arise. But at what cost do these options come? That is up for the business and you to decide. We’re getting very robust options in Exchange that can be leveraged with other technologies for high availability that have become more and more main stream. This means none of all this needs to be bought and implemented just for Exchange. They are already in place. Unless your IT “strategy” the last 10 years was run Windows 2000 & Exchange 2000 until the servers fall apart and we don’t have any more spares available on e-bay before we consider moving along.

System Center Virtual Machine Manager 2012 Using WSUS To Update Hyper-V Cluster Hosts & Other Fabric Servers

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One very neat feature in System Center Virtual Machine Manager 2012 (SCVMM2012), which is currently in Béta, is the integration with WSUS to automate the patching of Hyper-V cluster hosts (+ the Library servers, SCVMM servers and the update servers, i.e the fabric). The fact that SCVMM 2012 will give you the complete toolset to take care of this is yet a great addition to the functionality available in Virtual Machine Manager 2012. More and more I’m looking forward to using it in production as it has so many improvements and new features. Combine that with what’s being delivered in System Center Operations Manager (SCOM2012) and the other member of the System Center family and I’m quite happy with what is coming.

But let’s get back to the main subject of this blog. Using WSUS and SCVMM2012 to auto-update the Hyper-V cluster hosts without interruption to the virtual machines that are running on it. Up until now, we needed to script such a process out with PowerShell even tough having SCVMM2008R2 makes it easier since we have Maintenance Mode in that product which will evacuate all VMs from that particular host, one by one. The workflow of this script looks like this:

  • Place the Host Node in Maintenance Mode in SCOM 2007 R2 (So we don’t get pesky alerts)
  • Place the Host Node in Maintenance Mode in SCVMM2008R2 (this evacuates the VMs from the host via Live Migration to the other nodes in the cluster)
  • Patch the Host and restart it
  • Stop Maintenance Mode on the host node in SCVMM2008R2 (So it can be used to run VMs again)
  • Stop Maintenance Mode on the host node in SCOM 2007 (We want it to be monitored again)
  • Rinse & Repeat until all Host nodes are done. Depending on the size of the cluster you can do this with multiple nodes at the same time. Just remember that there can be only one Live Migration action taking place per node. That means you need at least 4 nodes to do something like Live migrate from Node A to Node B and Live Migrate from Node C to node D. So you need to work out what’s optimal for your cluster depending on load and number of nodes you have to work with.
  • Have the virtual machines redistributed so that the last host also gets its share or virtual machines

Now with SCVMM2012 we can do this out of the box using WSUS and all of this is achieved without ever interrupting any services provided by the guests as all virtual machines are kept running and are live migrated away from the host that will be patched. If you’re a shop that isn’t running System Center Configuration Manager you can still do this thanks to the use of WSUS and that’s great news.  There is an entire sub-section on the subject of Managing Fabric Updates in VMM 2012 already available on TechNet. But it goes beyond the Hyper-V host. It’s also the SCVMM server, the library server, and the Update Server that get patched. But don’t go wild now, that’s the entire scope of this. That means you still need regular WSUS or SCCM for patching the virtual machine guests and other physical servers. The aim of this solution is to patch your virtualization solution’s infrastructure as a separate entity, not your entire environment.

So how do we get this up and running? Well, it isn’t hard. Depending on your needs and environment you can choose to run WSUS and SCVMM on the same server or not. If you choose the latter please make sure you install the SWSUS Administration Console on the SCVMM server. This is achieved by downloading  WSUS 3.0 SP2 and installing it. Otherwise, just use the WSUS role from the roles available on Windows 2008 R2. This handles the prerequisites for you as well. It is also advisable to install the WSUS role on a separate server when your SCVMM 2012 Infrastructure is a highly available clustered one. For more information see http://technet.microsoft.com/en-us/library/gg675099.aspx . Time-saving tip: create a separate domain account for the WSUS server integration, it can not be the SCVMM 2012 service domain account.

Make sure you pay attention to the details in the documentation, don’t forget to install the WSUS 3.0 SP2 Administration Console on the SCVMM 2012 server or servers and to restart the SCVMM service when asked to. That will safe you some trouble. Also, realize that this WSUS Server will only be used for updating the SCVMM 2012 fabric and nothing else. So we do not configure anything except the operating system (W2K8R2) , and the languages needed. All other options & products that are not related to virtualization are unchecked as we don’t need them. Combine this with dynamic optimization to distribute the VM’s for you and you’re golden. A good thing to note here is that you’re completely in control. You as the virtualization infrastructure / SCVMM 2012 Fabric administrator control what happens regarding updates, service packs, …

You do need to get used to the GUI a bit when playing around with SCVMM2012 for the first time to make sure you’re in the right spot, but once you get the hang of it you’ll do fine. I’ll leave you with some screenshots of my lab cluster being scanned to check the compliance status and then being remediated. It works pretty neatly.

Here are the hosts being scanned.

You can right-click and select remediate per baseline or select the host and select remediate form context menu or the ribbon bar.

The crusader host is being remediated. I could see it being restarted in the lab.

New KB Article 2494016 Related to Windows Server 2008 SP1 Hyper-V: Stop error 0x0000007a When Using CVS in Redirected Access

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Well not a day after my blog post Extra Info on Clustering & Hyper-V with Dynamic Memory When You Start With Windows Server 2008 R2 SP1on important hotfixes for Hyper-V clustering with Windows Server 2008 R2 SP1 Microsoft releases a new hot fix for issue below. I’ll add it to the post to keep up to date.

Stop error 0x0000007a occurs on a virtual machine that is running on a Windows Server 2008 R2-based failover cluster with a cluster shared volume, and the state of the CSV is switched to redirected access

The KB article with instructions on how to get the hot fix is here: http://support.microsoft.com/kb/2494016/en-us?sd=rss&spid=14134

The scenario is detailed as follows:

Consider the following scenario:

  • You enable the cluster shared volume (CSV) feature on a Windows Server 2008 R2-based failover cluster.
  • You create a virtual machine on the CSV on a cluster node.
  • You start the virtual machine on the cluster node.
  • You move the CSV owner to another cluster node, and you change the state of CSV to redirected access.
  • The connection that is used for redirected access is switched to another connection when one of the following scenarios occurs:
    • The cable for local area network (LAN) is disconnected.
    • The related network adapter is disabled.
    • The connection is switched by using Failover Cluster Manager.

In this scenario, you receive a Stop error message that resembles the following in the virtual machine:

STOP 0x0000007a ( parameter1 , parameter2 , parameter3 , parameter4 )
KERNEL_DATA_INPAGE_ERROR

Note

  • The parameters in this Stop error message vary, depending on the configuration of the computer.
  • Not all "0x0000007a" Stop error messages are caused by this issue.
  • You may also receive other Stop error messages when this issue occurs. For example, you may receive a "0x0000004F" Stop error message.

Windows Hyper-V Server R2 SP1 is available for download

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Ever since Windows 2008 R2 SP1 became available people have been waiting for Windows Hyper-V Server R2 to catch up. The wait is over as last week Microsoft made it available on their website http://technet.microsoft.com/en-us/evalcenter/dd776191.aspx. That’s a nice package to have when it serves your needs and there ‘s little to argue about. Guidance on how to configure it and how to get remote management set up has been out for a while and is quite complete so that barrier shouldn’t stop you from using it where appropriate. If you’re staring out head over to José Barreto’s blog to get a head start and here’s some more information on the subject http://technet.microsoft.com/en-us/library/cc794756(WS.10).aspx and naturally there are some tools around to help out if needed and the Microsoft provided tools are not to you liking http://coreconfig.codeplex.com/. So there you go, now you have a free and very capable hypervisor available to the public that gives you high availability, Live Migration, Dynamic Memory, Remote FX and they even threw in their software iSCSI target 3.3 into the free package so you can build a free iSCSI SAN supported by Microsoft. Live is good.