Applies to: Exchange Server 2013

Topic Last Modified: 2012-10-16

Use the Restore-DatabaseAvailabilityGroup cmdlet as part of a datacenter switchover of a database availability group (DAG).

For information about the parameter sets in the Syntax section below, see Syntax.

Syntax

Restore-DatabaseAvailabilityGroup -Identity <DatabaseAvailabilityGroupIdParameter> [-ActiveDirectorySite <AdSiteIdParameter>] [-AlternateWitnessDirectory <NonRootLocalLongFullPath>] [-AlternateWitnessServer <FileShareWitnessServerName>] [-Confirm [<SwitchParameter>]] [-DomainController <Fqdn>] [-UsePrimaryWitnessServer <SwitchParameter>] [-WhatIf [<SwitchParameter>]]

Examples

EXAMPLE 1

This example activates member servers in the DAG DAG1 for the Active Directory site Portland. In this example, the values for the AlternateWitnessServer parameter and the AlternateWitnessDirectory parameter had been previously set by using the Set-DatabaseAvailabilityGroup cmdlet. Thus, there is no need to specify them here.

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Restore-DatabaseAvailabilityGroup -Identity DAG1 -ActiveDirectorySite Portland

EXAMPLE 2

This example activates member servers in the DAG DAG1 for the Active Directory site Redmond. In this example, the values for the AlternateWitnessServer parameter and the AlternateWitnessDirectory parameter are being set as part of the activation process.

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Restore-DatabaseAvailabilityGroup -Identity DAG1 -ActiveDirectorySite Redmond -AlternateWitnessServer CAS4 -AlternateWitnessDirectory D:\DAG1

Detailed Description

You can also use this cmdlet for disaster recovery purposes to restore functionality to a DAG that has lost quorum due to one or more DAG members being offline for an extended period. Before running this cmdlet, you must first run the Stop-DatabaseAvailabilityGroup cmdlet.

The Restore-DatabaseAvailabilityGroup cmdlet can be run against a DAG only when the DAG is configured with a DatacenterActivationMode parameter value of DagOnly. For more information about the DatacenterActivationMode parameter, see Datacenter Activation Coordination Mode.

You can use the Set-DatabaseAvailabilityGroup cmdlet to configure the value for the DatacenterActivationMode parameter.

The Restore-DatabaseAvailabilityGroup cmdlet performs several operations that affect the structure and membership of the DAG's cluster. This task does the following:

  • Forcibly evicts the servers listed on the StoppedMailboxServers list from the DAG's cluster, thereby reestablishing quorum for the cluster enabling the surviving DAG members to start and provide service.

  • Configures the DAG to use the alternate witness server if there is an even number of surviving DAG members, or a single surviving DAG member.

You need to be assigned permissions before you can run this cmdlet. Although all parameters for this cmdlet are listed in this topic, you may not have access to some parameters if they're not included in the permissions assigned to you. To see what permissions you need, see the "Database availability groups" entry in the High Availability and Site Resilience Permissions topic.

Parameters

Parameter Required Type Description

Identity

Required

Microsoft.Exchange.Configuration.Tasks.DatabaseAvailabilityGroupIdParameter

The Identity parameter specifies the name of the DAG being manipulated.

ActiveDirectorySite

Optional

Microsoft.Exchange.Configuration.Tasks.AdSiteIdParameter

The ActiveDirectorySite parameter specifies the site containing the DAG members to be restored.

AlternateWitnessDirectory

Optional

Microsoft.Exchange.Data.NonRootLocalLongFullPath

The AlternateWitnessDirectory parameter specifies the name of an alternate directory used to store witness data. The specified directory must not be in use by any other DAGs or used for any other purpose. This value can be populated ahead by using the Set-DatabaseAvailabilityGroup cmdlet.

AlternateWitnessServer

Optional

Microsoft.Exchange.Data.FileShareWitnessServerName

The AlternateWitnessServer parameter specifies the name of a new witness server for the DAG as part of a site activation process. This value can be populated ahead by using the Set-DatabaseAvailabilityGroup cmdlet.

Confirm

Optional

System.Management.Automation.SwitchParameter

The Confirm switch causes the command to pause processing and requires you to acknowledge what the command will do before processing continues. You don't have to specify a value with the Confirm switch.

DomainController

Optional

Microsoft.Exchange.Data.Fqdn

The DomainController parameter specifies the fully qualified domain name (FQDN) of the domain controller that writes this configuration change to Active Directory.

UsePrimaryWitnessServer

Optional

System.Management.Automation.SwitchParameter

The UsePrimaryWitnessServer parameter specifies that the DAG's currently configured witness server should be used if a witness is needed by the DAG members being activated.

WhatIf

Optional

System.Management.Automation.SwitchParameter

The WhatIf switch instructs the command to simulate the actions that it would take on the object. By using the WhatIf switch, you can view what changes would occur without having to apply any of those changes. You don't have to specify a value with the WhatIf switch.

Input Types

To see the input types that this cmdlet accepts, see Cmdlet Input and Output Types. If the Input Type field for a cmdlet is blank, the cmdlet doesn’t accept input data.

Return Types

To see the return types, which are also known as output types, that this cmdlet accepts, see Cmdlet Input and Output Types. If the Output Type field is blank, the cmdlet doesn’t return data.