Microsoft Exchange Server 2010 : Creating and Managing Database Availability Groups (part 4) - Configuring Database Availability Group Properties

4. Configuring Database Availability Group Properties

You can use the Exchange Management Console or the Exchange Management Shell to configure the properties of a database availability group, including the witness server and witness directory used by the database availability group. Using the Exchange Management Shell, you can configure additional properties, such as encryption and compression settings, network discovery, the TCP port used for replication, alternate file share witness settings, and data center activation coordination mode.

To view or modify the properties of an availability group, complete the following steps:

1. In the Exchange Management Console, expand the Organization Configuration node and then select the related Mailbox node. In the results pane, select the Database Availability Group tab to view existing availability groups.

2. Right-click the database availability group you want to work with and then select properties.

3. In the Properties dialog box, shown in Figure 5 you'll see a list of member servers, the witness server's fully qualified domain name, and the location of the witness directory on the witness server.

   

   Figure 5. View or modify properties of the availability group.

4. Using the Witness Server text box, you can specify a new witness server by entering the fully qualified domain name of the new witness server. This server should be in the same Active Directory forest as the member servers and cannot be a current or future member of the database availability group.

5. Using the Witness Directory text box, you can specify a new witness directory on the witness server. If the directory does not exist, it will be created on the witness server.

6. Click OK.

In the Exchange Management Shell, you can configure properties of database availability groups using the Set-DatabaseAvailabilityGroup cmdlet. Example 6 provides the syntax and usage.

Example 6. Set-DatabaseAvailabilityGroup cmdlet syntax and usage

Syntax

Set-DatabaseAvailabilityGroup -Identity DAGName
[-DatabaseAvailabilityGroupIpAddresses IPAddresses]
[-DatacenterActivationMode {"Off"|"DagOnly"}]
[-DiscoverNetworks] [-DomainController FullyQualifiedName]
[-NetworkCompression {"Disabled"|"Enabled"|"InterSubnetOnly"|"SeedOnly"}
[-NetworkEncryption {"Disabled"|"Enabled"|"InterSubnetOnly"|"SeedOnly"}
[-ReplicationPort TCPPort] [-AlternateWitnessServer ServerName]
[-AlternateWitnessServerDirectory DirectoryPath]
[-WitnessServer ServerName] [-WitnessServerDirectory DirectoryPath]


Usage

Set-DatabaseAvailability -Identity "EastCampusDAG1"
-NetworkCompression "Enabled" -NetworkEncryption "Enabled"
-ReplicationPort 33898 -DatacenterActivationMode "Off"

Options for working with encryption, compression. Options that weren't discussed include the datacenter activation coordinator mode, the alternate witness server, and alternate witness server directory. These options can be used as part of a datacenter switchover process. The alternate witness server must not be a part of the database availability group.

The data-center coordinator mode should be set for all database availability groups with three or more members that are extended to two or more physical locations. This mode cannot be enabled for groups with less than three members. When the datacenter coordinator is enabled, you can start, stop, and restore member servers in an availability group individually or collectively using the following:

• Start-DatabaseAvailabilityGroup Activates member Mailbox servers in a recovered data center after a data-center switchover, as part of the failback process to the recovered data center. This command sets the configuration and state so that the servers are incorporated into the operating database availability group and joined to the group's cluster. You use the –MailboxServer parameter to start a specific member server or the –ActiveDirectorySite parameter to start all members in a particular site.

  Start-DatabaseAvailabilityGroup -Identity DAGName
  [-MailboxServer ServerName | -ActiveDirectorySite SiteName]
  [-ConfigurationOnly <$true | $false>]
  [-DomainController FullyQualifiedName]

  Note

  You can also reactivate servers from a previously failed datacenter that has been restored to service. Before you can reactivate member Mailbox servers in a primary data center, the servers must first be integrated back into the operational database availability group. You reintegrate servers by running the Start-DatabaseAvailabilityGroup cmdlet and then using the Move-ActiveMailboxDatabase cmdlet to activate databases in the primary data center.

• Stop-DatabaseAvailabilityGroup Deactivates member Mailbox servers after a datacenter switchover. You use the –MailboxServer parameter to deactivate a specific member server or the –ActiveDirectorySite parameter to deactivate all members in a particular site.

  Stop-DatabaseAvailabilityGroup -Identity DAGName
  [-MailboxServer ServerName | -ActiveDirectorySite SiteName]
  [-ConfigurationOnly <$true | $false>]
  [-DomainController FullyQualifiedName]

• Restore-DatabaseAvailabilityGroup Activates member Mailbox servers in a standby data center. Typically, this process is performed after the failure or deactivation of the active member servers in a primary data center. You use the –ActiveDirectorySite parameter to activate all members in a particular site.

  Restore-DatabaseAvailabilityGroup -Identity DAGName
  [-ActiveDirectorySite SiteName]
  [-AlternateWitnessServer ServerName]
  [-AlternateWitnessDirectory DirectoryPath]
  [-DomainController FullyQualifiedName]