Restore-DatabaseAvailabilityGroup

Reference

Module:: ExchangePowerShell

Applies to:: Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

This cmdlet is available only in on-premises Exchange.

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 Exchange cmdlet syntax.

Syntax

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

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 this topic lists all parameters for the cmdlet, you may not have access to some parameters if they're not included in the permissions assigned to you. To find the permissions required to run any cmdlet or parameter in your organization, see Find the permissions required to run any Exchange cmdlet.

Examples

Example 1

Restore-DatabaseAvailabilityGroup -Identity DAG1 -ActiveDirectorySite Portland

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.

Example 2

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

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.

Parameters

-ActiveDirectorySite

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

Type:	AdSiteIdParameter
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False
Applies to:	Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

-AlternateWitnessDirectory

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.

Type:	NonRootLocalLongFullPath
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False
Applies to:	Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

-AlternateWitnessServer

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.

Type:	FileShareWitnessServerName
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False
Applies to:	Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

-Confirm

The Confirm switch specifies whether to show or hide the confirmation prompt. How this switch affects the cmdlet depends on if the cmdlet requires confirmation before proceeding.

Destructive cmdlets (for example, Remove-* cmdlets) have a built-in pause that forces you to acknowledge the command before proceeding. For these cmdlets, you can skip the confirmation prompt by using this exact syntax: -Confirm:$false.
Most other cmdlets (for example, New-* and Set-* cmdlets) don't have a built-in pause. For these cmdlets, specifying the Confirm switch without a value introduces a pause that forces you acknowledge the command before proceeding.

This cmdlet has a built-in pause, so use -Confirm:$false to skip the confirmation.

Type:	SwitchParameter
Aliases:	cf
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False
Applies to:	Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

-DomainController

The DomainController parameter specifies the domain controller that's used by this cmdlet to read data from or write data to Active Directory. You identify the domain controller by its fully qualified domain name (FQDN). For example, dc01.contoso.com.

Type:	Fqdn
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False
Applies to:	Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

-Identity

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

Type:	DatabaseAvailabilityGroupIdParameter
Position:	1
Default value:	None
Required:	True
Accept pipeline input:	True
Accept wildcard characters:	False
Applies to:	Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

-UsePrimaryWitnessServer

The UsePrimaryWitnessServer switch specifies that the DAG's currently configured witness server should be used if a witness is needed by the DAG members that are being activated. You don't need to specify a value with this switch.

Type:	SwitchParameter
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False
Applies to:	Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

-WhatIf

The WhatIf switch simulates the actions of the command. You can use this switch to view the changes that would occur without actually applying those changes. You don't need to specify a value with this switch.

Type:	SwitchParameter
Aliases:	wi
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False
Applies to:	Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

Inputs

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.

Outputs

Output 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.