Azure Storage Account:- Manual Failover

Rather happy with this preview feature announcement – currently in preview Geo-redundant storage (GRS) or Read Access-GRS accounts now have the option to manually fail over rather than wait on Azure to initiate the fail-over into the secondary region.

This is great news, not all “Disaster Recovery” scenarios now require Azure to initiate the fail-over, with a manual action you can now have the read/writes to happen in the secondary region

If the primary region for your geo-redundant storage account becomes unavailable for an extended period of time, you can force an account failover. When you perform a failover, all data in the storage account is failed over to the secondary region, and the secondary region becomes the new primary region. The DNS records for all storage service endpoints – blob, Azure Data Lake Storage Gen2, file, queue, and table – are updated to point to the new primary region. Once the failover is complete, clients can automatically begin writing data to the storage account using the service endpoints in the new primary region, without any code changes.

azure.microsoft.com

Now lets have a look at this new feature..

Please Note: As of writing this blog, the feature is only available in West US Central, West US 2.

This new feature is requested via PowerShell

Register-AzureRmProviderFeature -FeatureName CustomerControlledFailover -ProviderNamespace Microsoft.Storage

Create a GRS Storage Account in WestUS 2

$StorageAccountName = "tamopstest"
$StorageAccountLocation = "westus2"
$StorageAccountSKU = "Standard_GRS"
$StorageAccountRGName = "tamops-failover"

New-AzureRmStorageAccount -Name $StorageAccountName -SkuName $StorageAccountSKU -Location $StorageAccountLocation -ResourceGroupName $StorageAccountRGName

Viewing the Storage Account in the Portal, under Geo-replication settings you will see a button: Prepare for failover (preview)

Some points to note before failing over the the Secondary Region, below taken from the Portal:-

The storage account secondary endpoint will become the primary endpoint after failover completes. Please understand the following impact to your storage account before you initiate the failover:

• Your last sync time is <date/time>. You may lose any data after this time if you initiate the failover.
• After the failover completes, your storage account replication will be converted to a locally-redundant storage (LRS) account. You can convert your account to use geo-redundant storage (GRS) or read-access geo-redundant storage (RA-GRS).
• Once you re-enable GRS or RA-GRS replication on your storage account, Microsoft will replicate data to your new secondary region. Replication time is dependent on the amount of data to be replicated. Please note that there are bandwidth charges for this data transfer.

Lets fail-over using PowerShell

$StorageAccountName = "tamopstest"
$StorageAccountRGName = "tamops-failover"

Invoke-AzureRmStorageAccountFailover -ResourceGroupName $StorageAccountRGName -Name $StorageAccountName

Select “Yes” to the prompt and review the Portal Geo-replication Settings of the Storage Account

As mentioned above, once fail over has completed – the Storage Account will now have Locally-redundant storage (LRS) replication in the Secondary Region

Using Azure CLI

Create a GRS Storage Account in WestUS 2

$StorageAccountName = "tamopstestcli"
$StorageAccountRGName = "tamops-failover"
$StorageAccountLocation = "westus2"
$StorageAccountSKU = "Standard_GRS"
 
az storage account create `
    --name $StorageAccountName `
    --sku $StorageAccountSKU `
    --location $StorageAccountLocation `
    --resource-group $StorageAccountRGName

Lets fail-over using Azure CLI

$StorageAccountName = "tamopstestcli"

az storage account failover `
    --name $StorageAccountName

Thanks for reading, hopefully this new fail-over features comes out of preview rather soon!