Initiate a storage account failover (preview)
If the primary endpoint for your geo-redundant storage account becomes unavailable for any reason, you can initiate an account failover (preview). An account failover updates the secondary endpoint to become the primary endpoint for your storage account. Once the failover is complete, clients can begin writing to the new primary region. Forced failover enables you to maintain high availability for your applications.
This article shows how to initiate an account failover for your storage account using the Azure portal, PowerShell, or Azure CLI. To learn more about account failover, see Disaster recovery and account failover (preview) in Azure Storage.
An account failover typically results in some data loss. To understand the implications of an account failover and to prepare for data loss, review Understand the account failover process.
This article has been updated to use the new Azure PowerShell Az module. You can still use the AzureRM module, which will continue to receive bug fixes until at least December 2020. To learn more about the new Az module and AzureRM compatibility, see Introducing the new Azure PowerShell Az module. For Az module installation instructions, see Install Azure PowerShell.
Before you can perform an account failover on your storage account, make sure that you have performed the following steps:
- Register for the account failover preview. For information about how to register, see About the preview.
- Make sure that your storage account is configured to use either geo-redundant storage (GRS) or read-access geo-redundant storage (RA-GRS). For more information about geo-redundant storage, see Geo-redundant storage (GRS): Cross-regional replication for Azure Storage.
Important implications of account failover
When you initiate an account failover for your storage account, the DNS records for the secondary endpoint are updated so that the secondary endpoint becomes the primary endpoint. Make sure that you understand the potential impact to your storage account before you initiate a failover.
To estimate the extent of likely data loss before you initiate a failover, check the Last Sync Time property using the
Get-AzStorageAccount PowerShell cmdlet, and include the
-IncludeGeoReplicationStats parameter. Then check the
GeoReplicationStats property for your account.
After the failover, your storage account type is automatically converted to locally redundant storage (LRS) in the new primary region. You can re-enable geo-redundant storage (GRS) or read-access geo-redundant storage (RA-GRS) for the account. Note that converting from LRS to GRS or RA-GRS incurs an additional cost. For additional information, see Bandwidth Pricing Details.
After you re-enable GRS for your storage account, Microsoft begins replicating the data in your account to the new secondary region. Replication time is dependent on the amount of data being replicated.
To initiate an account failover from the Azure portal, follow these steps:
Navigate to your storage account.
Under Settings, select Geo-replication. The following image shows the geo-replication and failover status of a storage account.
Verify that your storage account is configured for geo-redundant storage (GRS) or read-access geo-redundant storage (RA-GRS). If it's not, then select Configuration under Settings to update your account to be geo-redundant.
The Last Sync Time property indicates how far the secondary is behind from the primary. Last Sync Time provides an estimate of the extent of data loss that you will experience after the failover is completed.
Select Prepare for failover (preview).
Review the confirmation dialog. When you are ready, enter Yes to confirm and initiate the failover.