In a previous blog post I explained how VM Monitoring can be configured in Window Server 2012. In this blog I will answer the three most frequently asked questions related to the VM Monitoring feature.
1) Why can I no longer make my Print Server role Highly Available in Windows Server 2012? I was able to do this in Windows Server 2008 R2.
In contrast to previous versions of Windows Server, Windows Server 2012 defines a highly available print server as a Hyper-V virtual machine(VM) running on a node in a cluster. A single virtual machine with the Print Server role installed can then be migrated from one node in the Hyper-V cluster to the other using either manual or automatic methods.
In Windows Server 2012, the print spooler service is no longer a clustered resource and instead the entire virtual machine is migrated from one Hyper-V node to the other. This new model provides the same seamless user experience as previous versions of Windows but with the following added benefits:
- Using Windows Server 2012 as the Hyper-V and failover clustering host allows access to the VM Monitoring feature. This allows greater flexibility and control over recovery actions.
- Windows Server 2012 Print Servers can utilize the Live Migration and Quick Migration features of Hyper-V.
- Windows Server 2012 Highly Available Print Servers are easier to deploy and have reduced complexity.
- Print devices and drivers are deployed the same as on a physical machine which provides consistency for management. When deployed in a virtual machine, availability can be enhanced using the VM Monitoring feature.
- Printer manufacturers will have a single driver so they can focus on higher quality and reduce the cost for creating drivers.
In a nutshell, using the VM Monitoring feature, the new print spooler HA model is able to streamline the deployment and management while providing higher availability for your users.
For additional information please refer to:
- The default VM Monitoring configuration will reboot or failover the virtual machine for every third Print Service failure in a 15 minute window. The duration of this virtual machine reboot is typically in the order of seconds. During this interval the print service will not be available. Later in this blog I will explain how this default recovery action can be customized.
- During patching, the Print Service on the hosted virtual machine can be temporarily unavailable, if a reboot is required. The impact of this planned downtime can be mitigated by having an additional Print Server hosted on a Hyper-V node as a backup.
2) I want to configure VM Monitoring for a mission critical Virtual Machine. I do not want to take automated recovery actions such as rebooting my VM. I want to be notified when my VM encounters a critical condition so that my administrator can investigate the failure. How do I do this?
I have System Center Operations Manager deployed on my host (cluster node hosting the VM). How do I configure Operations Manager to work with VM Monitoring?
I want to customize the recovery action taken by the VM Monitoring. I don’t want to restart the VM or failover the VM on a failure. How do I do this?
If the “Enable automatic recovery for application health monitoring” option is deselected, the cluster service does not take any automatic recovery actions when a VM critical condition occurs. It does however log event ID 1250, to indicate that a critical condition occurred in your VM. To deselect this setting:
Using Failover Cluster Manager:
A) Select the VM that you want to configure this setting for
B) Click on the Resources tab
C) Right click on the Virtual Machine resource and select the Properties option.
D) Select the Settings tab and uncheck Enable automatic recovery for application health monitoring
Using Windows PowerShell©
a) Open a Windows PowerShell shell as an Administrator
b) Set the EmbeddedFailureAction property for the VM resource:
(Get-ClusterResource “*e test-VM”).EmbeddedFailureAction = 1
Note: To re-enable automatic recovery actions on VM Critical failures this property should be set to 2 (default).
You can monitor Event 1250 to customize recovery action on VM Critical failures. Some options include:
A) Setting up a Cluster Scheduled task to carry out a desired sequence of actions on the occurrence of the VM event or service failure being monitored e.g.: Initiate a live migration on a VM network failure or send an email to a cluster administrator indicating the failure condition.
B) Configure System Center Operations Manager to take recovery actions when the event is triggered on the host.
C) Use a 3rd party solution such as Symantec ApplicationHA© for Hyper-V which provides advanced customization of recovery actions.
The administrator can investigate the VM in critical state as follows:
a) Log onto the VM
b) Launch Task Scheduler
c) Navigate to the Microsoft/FailoverClustering/VM Monitoring node
d) Examine when the last event or service failure occurred.
e) Once the failure has been examined and appropriate recovery actions taken, the VM can be removed from Critical State by running the following Windows PowerShell cmdlet as an Administrator on the guest:
3) The Virtual Machine I want to monitor is not in the same domain as the cluster node it is hosted on. Can I configure VM Monitoring?
In this configuration VM Monitoring needs to be configured using Windows PowerShell by logging into the guest (virtual machine).
- Failover Clustering Admin Tools installed in the guest. This installs the FailoverClusters PowerShell module
Steps to configure in the guest using PowerShell:
a) Open a Windows PowerShell shell as an Administrator
b) Run the Add-ClusterVMMoniteredItem cmdlet inside the guest to configure monitoring
Example: Add-ClusterVMMonitoredItem –service spooler
Clustering and High Availability