Exchange Server Pro » CCR

How to Move the File Share Witness for Exchange 2007 CCR Clusters

Paul Cunningham — Fri, 29 Jul 2011 14:21:22 +0000

An Exchange Server 2007 CCR cluster uses a cluster quorum configuration called Node and File Share Majority.

This means that the cluster has two servers that are the cluster nodes themselves, and a third server that is the File Share Witness server. The role of the File Share Witness server is to allow a majority of nodes to “vote” on which cluster node should be the active node.

The File Share Witness server is simply a server configured with a file share that the cluster service has access to. During failure scenarios each cluster node (that is still online) attempts to get an SMB lock on the file share to see if it can secure the majority of “votes” in the cluster.

The normal practice is to locate the File Share Witness for an Exchange Server 2007 CCR cluster on a Hub Transport server in the same site or data center as the cluster nodes, or the same data center of at least one of the nodes in a geo-cluster model. It is not mandatory to place it on a Hub Transport server though.

In some situations you may need to move this File Share Witness role to another server. This is a fairly simple process for Exchange Server 2007 CCR clusters running on Windows Server 2008.

In this demonstration I will move the File Share Witness from server HO-EX2007-HT1 to HO-EX2007-CA1 for the clustered mailbox server HO-EX2007-MB1.

Creating the File Share

The first step is to create the file share on the new File Share Witness server. Create a new folder named _FSW.

Open the Properties of the folder and navigate to the Sharing tab, then click Advanced Sharing.

Tick the box to share the folder, and then click Permissions.

Remove the default share permissions, and then add the computer account for the cluster with Full Control permissions.

Click OK, and OK to apply the share permissions, and then click on the Security tab of the folder properties.

Edit the permissions to grant the computer account for the cluster Full Control of the folder.

Click OK and apply all the changes you’ve just made.

Change the File Share Witness for the Failover Cluster

Log on to one of the cluster nodes and open Failover Cluster Management from the Administrative Tools. Right-click the cluster name and choose More Actions -> Configure Cluster Quorum Settings.

Click Next, then select Node and File Share Majority, and click Next to continue.

Enter the UNC path to the new file share that you created earlier, click Next, and then click Next again to configure the cluster with the new File Share Witness.

Click Finish when the operation has completed.

The File Share Witness role has now been moved to the new server.

Testing the New File Share Witness

There are a few ways you can test the new cluster configuration.

You can use the Manage Clustered Mailbox Server wizard to test the failover of the cluster between the two nodes.

You can also create unplanned failover scenarios, although if you do decide to do this I recommend making sure you do it outside of business hours, after a successful backup, and ensure the storage groups are in a healthy replication state with no copy or replay queues.

You can use Failover Cluster Management to stop the cluster service on the active node, which will cause a failover. Make sure you start it again when you’re done with the test.

Or you can simply pull out the network cable from the active node, which will have the same effect.

In these unplanned failover scenarios when one node is unavailable the File Share Witness is used to form a majority so that the other cluster node can bring the cluster resources online. You can verify that the FSW arbitration took place by generating the cluster log and opening it in Notepad.

C:\>cluster log /g
Generating the cluster log(s) ...
The cluster log has been successfully generated on node 'ho-ex2007-node2'...
The cluster log has been successfully generated on node 'ho-ex2007-node1'...

Look at the cluster.log file in C:\Windows\System32\Cluster\Reports and you should see entries for the FSW arbitration.

File Share Witness : Beginning arbitration ...
File Share Witness : Opening file \\ho-ex2007-ca1\ho-ex2007-mb1_fsw\82c44535-d765-4fbe-8ad8-0de1c04a87a6\Witness.log.
File Share Witness : Locking file \\ho-ex2007-ca1\ho-ex2007-mb1_fsw\82c44535-d765-4fbe-8ad8-0de1c04a87a6\Witness.log.

After your testing is complete just be sure to reconnect any network cables, start cluster services if you stopped them, and move the cluster group back to the preferred active node.

Get more Exchange Server tips at ExchangeServerPro.com

How to Move Storage Groups and Databases in an Exchange 2007 CCR Cluster

Paul Cunningham — Tue, 14 Jun 2011 13:19:00 +0000

Exchange Server 2007 makes it fairly easy to move storage group and database paths using a few simple commands. Except if you’re running an Exchange 2007 CCR cluster.

For CCR clusters the technique used for standalone Exchange 2007 mailbox servers has to be modified slightly to account for the fact that the CCR cluster can’t move the transaction logs and mailbox database files itself. Instead the administrator must move the files manually, and issue commands to update the storage group and database configurations to the new paths.

So if the process is different (some would say it is harder) why not take another approach?

For example, why not just delete the storage group and database you don’t want, and create new ones in the correct paths? This might be feasible for the default storage group and database created when the cluster was first installed, but once you have added mailboxes it is no longer an option.

In that case, why not just create the new storage group and database and migrate the mailboxes instead? That might work fine in some cases (certainly that’s how I’ve done it sometimes in the past), but if there is a lot of mailboxes you can run into problems managing the amount of transaction logging that the mailbox moves create. It can also take a lot longer than simply moving the storage group and database.

Preparing to Move a Storage Group in an Exchange 2007 CCR Cluster

Before you move a storage group in an CCR cluster I recommend that you first back up the database in that storage group. By running a full backup you:

Truncate the transaction logs, which reduces the amount of data that needs to be moved
Give yourself a very recent back up to restore from if something goes wrong

Next check the copy and replay queues to make sure they are up to date.

[PS] C:\>Get-StorageGroupCopyStatus

Name                      SummaryCopySt CopyQueueLeng ReplayQueueL
                          atus          th            ength
----                      ------------- ------------- ------------
First Storage Group       Healthy       0             0

You should also make sure the new storage paths are properly configured and ready to be used in production.

Moving a Storage Group and Mailbox Database in an Exchange 2007 CCR Cluster

The first step is to suspend replication for the storage group.

[PS] C:\>Suspend-StorageGroupCopy "First Storage Group"

Confirm
Are you sure you want to perform this action?
Suspending Storage Group Copy "First Storage Group".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help

Next, dismount the mailbox database.

[PS] C:\>Dismount-Database "First Storage Group\Mailbox Database"

Confirm
Are you sure you want to perform this action?
Dismounting database "First Storage Group\Mailbox Database".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help
(default is "Y"):y

With replication suspended and the database dismounted you can now move the files by simply copying them in Windows Explorer to the new locations. You must do this step on both cluster nodes, and make sure that the path matches on both nodes.

After copying the files the next step is to update the configuration of the storage group with the new folder path. Note the use of the -ConfigurationOnly switch on this command.

[PS] C:\>Move-StorageGroupPath "First Storage Group" -SystemFolderPath E:\SG1 -LogFolderPath E:\SG1 -ConfigurationOnly

Confirm
Are you sure you want to perform this action?
Moving path of storage group "HO-EX2007-MB1.exchangeserverpro.net\First Storage Group".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help
(default is "Y"):y

Now the configuration of the mailbox database is also updated with the new folder path. Again note the use of the -ConfigurationOnly switch.

[PS] C:\>Move-DatabasePath "First Storage Group\Mailbox Database" -EdbFilePath '
F:\DB1\Mailbox Database.edb' -ConfigurationOnly

Confirm
This operation will skip the safety check and make the change to the Active
Directory directory service directly. Do you want to continue?
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help
(default is "Y"):y

Confirm
Are you sure you want to perform this action?
Moving database path "First Storage Group\Mailbox Database".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help
(default is "Y"):y

Now we can mount the database again.

[PS] C:\>Mount-Database "First Storage Group\Mailbox Database"

Finally, resume replication for the storage group.

[PS] C:\>Resume-StorageGroupCopy "First Storage Group"

The storage group and mailbox database have now been moved to the new locations and are back online. You can verify the health of the storage group by running Get-StorageGroupCopyStatus.

[PS] C:\>Get-StorageGroupCopyStatus

Name                      SummaryCopySt CopyQueueLeng ReplayQueueL
                          atus          th            ength
----                      ------------- ------------- ------------
First Storage Group       Healthy       0             0

You can also use Test-ReplicationHealth to test the CCR cluster.

[PS] C:\>Test-ReplicationHealth

Server          Check                      Result     Error
------          -----                      ------     -----
HO-EX2007-NODE1 PassiveNodeUp              Passed
HO-EX2007-NODE1 ClusterNetwork             Passed
HO-EX2007-NODE1 QuorumGroup                Passed
HO-EX2007-NODE1 FileShareQuorum            Passed
HO-EX2007-NODE1 CmsGroup                   Passed
HO-EX2007-NODE1 NodePaused                 Passed
HO-EX2007-NODE1 DnsRegistrationStatus      Passed
HO-EX2007-NODE1 ReplayService              Passed
HO-EX2007-NODE1 DBMountedFailover          Passed
HO-EX2007-NODE1 SGCopySuspended            Passed
HO-EX2007-NODE1 SGCopyFailed               Passed
HO-EX2007-NODE1 SGInitializing             Passed
HO-EX2007-NODE1 SGCopyQueueLength          Passed
HO-EX2007-NODE1 SGReplayQueueLength        Passed

As a final test you can also verify that MAPI connectivity is working.

[PS] C:\>Test-MAPIConnectivity

MailboxServer      Database           Result    Latency(MS) Error
-------------      --------           ------    ----------- -----
ho-ex2007-mb1      Mailbox Database   Success             8

Get more Exchange Server tips at ExchangeServerPro.com

Exchange 2007 CCR: Continuous Replication is in a Failed, Seeding, or Suspended State

Paul Cunningham — Fri, 25 Mar 2011 14:13:39 +0000

You may encounter an error with Exchange Server 2007 CCR clusters when trying to move the clustered mailbox server between nodes.

[PS] C:\>Move-ClusteredMailboxServer exchcluster1 -TargetMachine clunode1 -MoveComment "Testing failover"

Move-ClusteredMailboxServer : Continuous replication is in a failed, seeding, or suspended state on 'exchcluster1-db1'. Move-ClusteredMailboxServer cannot be performed if one or more of the server's storage group copies are in failed, seeding or suspended states.

This can occur when the storage groups are in a state of “Initializing”. This state can occur on storage groups in which the mailbox database is mounted but a new transaction log has not been written and closed (common when the database has no mailboxes on it or very low volume of email to and from the mailboxes on it). You can view the status of the storage groups using Get-StorageGroupCopyStatus.

[PS] C:\>Get-StorageGroupCopyStatus

Name                      SummaryCopySt CopyQueueLeng ReplayQueueL
                          atus          th            ength
----                      ------------- ------------- ------------
exchcluster1-db1           Initializing  0             0
exchcluster1-db2           Initializing  0             0

You can resolve the issue by dismounting and mounting the mailbox databases. To dismount all mailbox databases on a server use the following command.

[PS] C:\>Get-MailboxDatabase -server exchcluster1 | Dismount-Database -confirm:$false

To mount them again use this command.

[PS] C:\>Get-MailboxDatabase -server exchcluster1 | mount-Database -confirm:$false

The storage groups should now be in a healthy state.

[PS] C:\>Get-StorageGroupCopyStatus

Name                      SummaryCopySt CopyQueueLeng ReplayQueueL
                          atus          th            ength
----                      ------------- ------------- ------------
exchcluster1-db1           Healthy       0             0
exchcluster1-db2           Healthy       0             0

Once they are healthy you can move the clustered mailbox server to the other node.

Get more Exchange Server tips at ExchangeServerPro.com

Exchange Server 2007 High Availability

Paul Cunningham — Fri, 07 Aug 2009 04:32:26 +0000

Over at TheEmailAdmin.com I’ve published a five part series on Exchange Server 2007 high availability.

Part 1 – Basic Concepts of Exchange Server 2007 High Availability
Part 2 – How to use Local Continuous Replication
Part 3 – How to use Single Copy Clusters
Part 4 – How to use Cluster Continuous Replication
Part 5 – How to use Standby Continuous Replication

Get more Exchange Server tips at ExchangeServerPro.com

Exchange Server 2007 CCR recommendations

Paul Cunningham — Mon, 17 Nov 2008 20:00:00 +0000

From Tales of a System Administrator come these recommendations for Exchange 2007 CCR deployments:

Having had Cluster Continuous Replication in place now for about a year, I’ve derived some of my own best practice recommendations that might not be found within the official Microsoft documentation.

Although these recommendations are based on a very solid and stable production environment…anything bad or job search inducing that happens as a result of implementing them in your environment is not my responsibility.

Read the rest…

Link: My “unofficial” Exchange Server 2007 CCR recommendations

Get more Exchange Server tips at ExchangeServerPro.com

Exchange Server Pro » CCR

How to Move the File Share Witness for Exchange 2007 CCR Clusters

Creating the File Share

Change the File Share Witness for the Failover Cluster

Testing the New File Share Witness

Related posts:

How to Move Storage Groups and Databases in an Exchange 2007 CCR Cluster

Preparing to Move a Storage Group in an Exchange 2007 CCR Cluster

Moving a Storage Group and Mailbox Database in an Exchange 2007 CCR Cluster

Related posts:

Exchange 2007 CCR: Continuous Replication is in a Failed, Seeding, or Suspended State

Related posts:

Exchange Server 2007 High Availability

Related posts:

Exchange Server 2007 CCR recommendations

Related posts: