Topic Last Modified: 2014-02-24

Invokes the failback process for a Lync Server 2013 pool. Failback is used after a pool has failed over and the users of that pool have been "failed over" to a backup pool. (That simply means users who were signed on to the failed pool are automatically signed on to the backup pool.) When the failed pool has been restored, the fail back process signs the failed-over users back to their original pool. This cmdlet was introduced in Lync Server 2013.


Invoke-CsPoolFailBack -PoolFqdn <Fqdn> [-Confirm [<SwitchParameter>]] [-DisasterMode <SwitchParameter>] [-Force <SwitchParameter>] [-SkipDataVerification <SwitchParameter>] [-WaitTime <TimeSpan>] [-WhatIf [<SwitchParameter>]]


Example 1

In Example 1, failback is invoked for the pool

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Invoke-CsPoolFailback -PoolFqdn ""

Detailed Description

The pool failover process provides a way for administrators to quickly restore service to users if the Registrar pool they have logged on to should suddenly become unavailable. If a pool fails, users will automatically be signed off from Lync Server 2013; if they immediately try to log back on, they will be redirected to their specified backup pool.

To restore service to these users, administrators can run the Invoke-CsPoolFailOver cmdlet against the pool that is not currently available. Doing this will allow users to sign on to Lync Server using the designated backup pool, and give these users access to all Lync Server services and functionality. Note that users will not be rehomed on the backup pool; they will simply be allowed to log on and make use of that pool until their home pool has been restored. For example, if Pool A fails, users will be able to log on to Pool B (with complete functionality) until Pool A has been restored.

When the failed pool is once more up and running, administrators can then run the Invoke-CsPoolFailBack cmdlet in order to "fail back" users of that pool. If a user is currently logged on to the backup pool then he or she will be redirected back to their home pool after service has been restored.

To return a list of all the role-based access control (RBAC) roles this cmdlet has been assigned to (including any custom RBAC roles you have created yourself), run the following command from the Windows PowerShell command-line interface prompt:

Get-CsAdminRole | Where-Object {$_.Cmdlets –match "Invoke-CsPoolFailback"}

Lync Server Control Panel: The functions carried out by the Invoke-CsPoolFailback cmdlet are not available in the Lync Server Control Panel.


Parameter Required Type Description




Fully qualified domain name of the pool being failed back. For example:-PoolFqdn ""

The pool FQDN used during failback must be the same FQDN used during failover.




Prompts you for confirmation before executing the command.




Enables administrators to invoke pool failback even if the backup pool is currently unavailable. When you use this parameter, data generated by the failed-over users on the backup pool will be lost.




Suppresses the display of any non-fatal error message that might arise when running the command.




When specified, failback will begin immediately without first attempting to verify data.




Specifies the maximum amount of time the cmdlet should wait before synching data. Time values must be express using the format hours:minutes:seconds; for example, the following syntax sets the wait time to 1 minute and 30 seconds (00 hours:01:minutes:30 seconds):


The default value is 15 seconds.




Describes what would happen if you executed the command without actually executing the command.

Input Types

None. The Invoke-CsPoolFailBack cmdlet does not accept pipelined input.

Return Types


See Also