Testing Failover Clusters
After all the desired
cluster nodes to the failover cluster are added and failover and
failback configuration options are set for each Services and
Applications group, each group should be verified for proper operation
on each cluster node. For these tests to be complete, failover and, when
applicable, failback of cluster groups need to be tested. They can be
tested by simulating a cluster resource failure or by manually moving
the Services and Applications groups between nodes.
Testing Services and Applications Groups Using Manual Failover
To manually failover or move a Services and Applications group between failover cluster nodes, perform the following steps:
1. | Log
on to one of the Windows Server 2008 R2 cluster nodes with an account
with administrator privileges over all nodes in the cluster.
| 2. | Click Start, click All Programs, click Administrative Tools, and select Failover Cluster Manager.
| 3. | When
the Failover Cluster Manager console opens, if necessary type in the
name of the local cluster node to connect to the cluster.
| 4. | In the tree pane, select the cluster name, expand it, and select Services and Applications.
| 5. | Expand Services and Applications and select the desired group. For this example, the CLUSTERFS file server group will be used.
| 6. | In the tasks pane, note the current owner of the group.
| 7. | In
the tree pane, right-click the desired group, select Move This Service
or Application to Another Node, and select any of the desired available
nodes, as shown in Figure 12,
to move the group to NODE02. A confirmation dialog box will open to
confirm moving the group to the alternate node; confirm the move to
continue by pressing the Move CLUSTERFS to NODE02 button.
| 8. | The
group will be moved to the chosen node and when the group is back
online it will be reflected as Status: Online in the tasks pane. Close
the Failover Cluster Manager console and log off of the server.
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Simulating the Failure of a Cluster Resource
Simulating a cluster
resource failure can be easily accomplished using the Failover Cluster
Manager console. Each resource has its own properties and simulating a
failure usually initiates the startup or restoration of the resource
back to an online state. After the failure threshold is reached, the
Services and Applications group is taken offline, moved to another
available node, and brought back online. To simulate the failure of a
cluster resource and test the failover of a group, perform the following
steps:
1. | Log
on to one of the Windows Server 2008 R2 cluster nodes with an account
with administrator privileges over all nodes in the cluster.
| 2. | Click Start, click All Programs, click Administrative Tools, and select Failover Cluster Manager.
| 3. | When
the Failover Cluster Manager console opens, if necessary type in the
name of the local cluster node to connect to the cluster.
| 4. | In the tree pane, select the cluster name, expand it, and select Services and Applications.
| 5. | Expand Services and Applications and select the desired group. For this example, the CLUSTERFS file server group will be used.
| 6. | In the tasks pane, scroll down to locate the File Server cluster resource.
| 7. | Right-click the File Server resource, and select Properties.
| 8. | On
the File Server Property page, select the Policies tab and review the
resource failure configuration. The default configuration allows for one
service restart after failure within a period of 15 minutes. If a
second failure occurs within the threshold of 15 minutes, the entire
group is taken offline, moved to an alternate node, and brought back
online. This is controlled by checking the If Restart Is Unsuccessful,
Fail Over All Resources in This Service or Application check box.
| 9. | Close the File Server Property pages.
| 10. | Back
in the tasks pane of the Failover Cluster Manager console, right-click
the File Server resource, select More Actions, and click Simulate
Failure of This Resource, as shown in Figure 13. The resource will be failed and the cluster will attempt to automatically restart the File Server resource.
| 11. | When
the simulation is started, a confirmation is required; click the
appropriate button to allow for the resource failure simulation to be
processed.
| 12. | After
the File Server resource is automatically restarted, perform the
resource failure simulation again within 15 minutes. This time, the
entire group is taken offline and moved to the other node where it will
be brought back online.
| 13. | When
the simulation is started, a confirmation is required; click the
appropriate button to allow for the resource failure simulation to be
processed.
| 14. | If necessary, scroll up in the tasks pane to verify that the group has been moved to the alternate cluster node.
| 15. | Close the Failover Cluster Manager console and log off of the server.
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Failover Cluster Maintenance
Services and applications
are deployed on failover clusters based on the fact that they are
critical to business operations. The reliability of each cluster node is
very important and making any changes to the software or hardware
configuration of each node can compromise this reliability. Before any
changes are implemented on a production failover cluster, a few
premaintenance tasks should be performed.
Premaintenance Tasks
Before maintenance is run on a
cluster node or the entire failover cluster, several tasks should be
completed. To prepare a cluster node for maintenance, do the following:
1. | Whether
you’re planning a software or hardware upgrade, research to see whether
the changes will be supported on Windows Server 2008 R2 failover
clusters.
| 2. | Log
on to one of the Windows Server 2008 R2 cluster nodes with an account
with administrator privileges over all nodes in the cluster.
| 3. | Click Start, click All Programs, click Administrative Tools, and select Failover Cluster Manager.
| 4. | When
the Failover Cluster Manager console opens, if necessary type in the
name of the local cluster node to connect to the cluster.
| 5. | In
the tree pane, select the cluster name, and in the tree pane, note the
Current Host Server. If the Current Host Server is the node that will be
taken offline for maintenance, the cluster will be automatically moved
to an alternate node if the maintenance node is rebooted.
| 6. | In the tree pane, select and expand Services and Applications to reveal each of the groups.
| 7. | Select
each group and in the tasks pane, note which node is the Current Owner
of the move. Manually move each group to the node that will remain
online if any of the groups are currently running on the node that will
be taken offline for maintenance.
| 8. | After
all the groups are moved to a node that will remain online, in the tree
pane, expand Nodes to reveal all of the nodes in the failover cluster.
| 9. | Locate the node that will be taken offline for maintenance, right-click the node, and select Pause.
| 10. | When
the node is paused, resources cannot failover and come online and the
system can have the software and/or hardware configuration or updates
applied and, if necessary, rebooted.
| 11. | After
the maintenance tasks are completed, the node can be configured to be
active in the failover cluster by right-clicking the node in the
Failover Cluster Manager console and selecting Resume.
| 12. | When
the node resumes operation, if necessary, move the groups to this node
and perform the maintenance tasks on the remaining nodes in the cluster.
| 13. | When
the maintenance tasks have been completed on all of the failover
cluster nodes, close the Failover Cluster Manager console and log off of
the server.
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Removing Nodes from a Failover Cluster
Cluster nodes can be removed from a cluster for a number of reasons, and this process can be accomplished quite easily.
Note
If you’re removing nodes from
a cluster that utilizes the Node Majority Quorum model, be sure that a
majority of the nodes remain available; otherwise, the cluster might be
shut down. If this is not possible, the Quorum model might need to be
changed before a node is removed from the failover cluster.
To remove a node from a failover cluster, perform the following steps:
1. | Log
on to one of the Windows Server 2008 R2 cluster nodes with an account
with administrator privileges over all nodes in the cluster.
| 2. | Click Start, click All Programs, click Administrative Tools, and select Failover Cluster Manager.
| 3. | When
the Failover Cluster Manager console opens, if necessary type in the
name of the local cluster node to connect to the cluster.
| 4. | In the tree pane, select the cluster name, expand it, and select Nodes.
| 5. | Expand Nodes to reveal all of the cluster nodes.
| 6. | Right-click on the node that will be removed from the cluster, select More Actions, and click Evict.
| 7. | A
confirmation window opens. Select the option to evict the desired node
from the cluster. After the process starts, if the cluster and/or any
Services and Applications groups are running on this node, they will be
moved to a remaining node before this node is removed from the cluster.
| 8. | After the node is removed, close the Failover Cluster Manager console and log off of the server.
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Cluster Migration and Upgrades
If an organization currently
supports Windows Server 2003 clusters, the nodes in the cluster cannot
be upgraded to Windows Server 2008 R2 failover cluster nodes. This is
mainly because the requirements of Windows Server 2003 server clusters
and Windows Server 2008 R2 failover clusters are very different. Even
hardware requirements between Windows Server 2008 and Windows Server
2008 R2 are different in terms of what actual configurations have been
tested and are certified for failover clusters on each operating system
version. Windows Server 2008 R2 does provide a tool that can be used to
collect data and migrate built-in Windows services between Windows
Server 2003 server clusters or other Windows Server 2008 or Windows
Server 2008 R2 failover clusters to a destination Windows Server 2008 R2
failover cluster. For more information on migrating services between
Windows Server 2003 and Windows Server 2008 failover clusters to Windows
Server 2008 R2, review the Help topic “Migrating Settings to a Failover
Cluster Running Windows Server 2008 R2” in the failover clusters Help
file. Note that any application or service that was able to run on a
Windows Server 2008 failover cluster will also work on a Windows Server
2008 R2 failover cluster; only the hardware that is supported may be
different.
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