Microsoft Azure’s storage solutions offer ways to safeguard your data against loss and providing high availability. Let’s take a look at configuring storage redundancy within Azure which is an important topic for production and those preparing for the AZ-104 exam.
Azure Storage account brief overview
An Azure storage account is a construct in Azure that contains your data objects. These data objects include blobs, files, queues, and other things like tables. The Azure storage account is a unique namespace, making the storage data accessible from anywhere in the world.
As important as data is for most organizations, protecting the data is a matter of using a multi-faceted approach. However, at the core of the methodology to protect the data is storage redundancy. Microsoft Azure has several built-in storage redundancy options that can help protect data.
What is Azure Storage Redundancy?
Storage redundancy in Azure is designed to replicate your data for high availability. Keep in mind that regardless of which redundancy option you choose, Azure replicates your data three times in the primary region. In addition, Azure offers several redundancy options, with each one suited for different needs. Let’s look at these storage redundancy options and how data is replicated to understand how they affect your data strategy.
Read-access geo redundant storage
Read-Access Geo-Redundant Storage (RA-GRS) is an Azure Storage option that replicates your data to a secondary, geographically distant region. It does this for high availability and durability. You can extend the capabilities of Geo-Redundant Storage (GRS) with read-only access to your data in the secondary region. This means your app or users can have access to the data even before a failover is initiated.
This ensures that your application can access data even if the primary region becomes unavailable, enhancing data availability and business continuity.
Zone Redundant Storage GZRS: Enhancing Data Availability
Zone Redundant Storage (ZRS) replicates your data synchronously across three Azure availability zones in the primary region. An availability zone is basically in its simplest terms, an Azure data center. So, if there is an issue with the specific Azure data center where your data is located, this setup protects your data from zone-level failures. Storing your data in separate availability zones makes an excellent choice for applications requiring high availability without geographic replication
Locally Redundant Storage (LRS)
Locally Redundant Storage (LRS) is a type of Azure redundancy storing three copies of your data in a single data center. Your storage account synchronously copies data to the other locations. It is cost efficient and good for non-critical applications. With this type of data redundancy you want to make sure it is backed up and can be recovered.
Geo-Redundant Storage (GRS)
This type of storage is used when you need high durability and availability for your application data. When selected, it replicates your data to a second region that is geographically far from the primary region. This geo zone redundant storage protects against geo-centric cloud outages or other disasters.
Understanding Azure Availability Zones
Azure Availability Zones are physically separate locations within an Azure region. Each zone is made up of one or more data centers equipped with independent power, cooling, and networking. The use of availability zones is crucial in designing highly available applications.
Primary and Secondary Regions in Azure Storage
Geo-redundant storage, using either GRS or GZRS, copies your data to a separate geographical location in a backup region. This safeguards the data against regional disruptions.
In setups employing GRS or GZRS, the backup region’s data remains inaccessible for user or application use until a failover event is triggered. This event prompts an update to the DNS settings managed by Azure Storage. It effectively reassigns the secondary location as the new primary region access point for your storage resources.
During the transition, access to your data is temporarily suspended. Once the failover is finished, normal operations resume. Then it allows data reading and writing activities in the newly designated primary region.
The concept of primary and secondary regions is central to understanding Azure’s geo-redundant options. The primary region hosts the active copy of your data, while the secondary region serves as a passive backup, activated if the primary region becomes unavailable.
Plan for data loss between primary and secondary regions
Replication between the primary and secondary regions replicates data asynchronously. It means the secondary region will always be behind compared to the data contained in the primary region.
Accessing geo-redundant data
Accessing data in a geo-redundant setup requires understanding the differences between GRS and Read-Access Geo-Redundant Storage (RA-GRS). RA-GRS allows you to read data from the secondary region, providing a higher read availability.
Configuring storage redundancy in Azure storage
Let’s see how we can configure storage accounts with the desired redundancy option. Log into the Azure Portal, navigate to Storage accounts and create a new storage account.
In the Create a storage account wizard, you will see on the Basics tab, the ability to configure the redundancy for the new storage account.
You can also reconfigure redundancy for an existing storage account. Navigate to Storage accounts > yourstorageaccount and then click redundancy.
You will see the screen below:
If you click the dropdown menu, you will see the following options:
- Locally-redundant storage (LRS)
- Geo-redundant storage (GRS)
- Read-access geo-redundant storage (RA-GRS)
- Zone-redundant storage (ZRS)
Make your redundancy option selection and click the Save button.
Azure storage redundancy: Best practices
To benefit from Azure storage redundancy, it’s important to follow best practices. This includes regular monitoring, implementing failover strategies, and understanding the cost implications of different redundancy options.
Choosing the right redundancy depends
Selecting the appropriate redundancy option for your storage account is an important decision. There are many factors to consider. Note the following: your application’s availability requirements, data access patterns, regulatory compliance needs, and costs.
High availability and disaster recovery with Azure storage
Beyond redundancy, Azure offers solutions for high availability and disaster recovery. Redundancy does not protect you from things like a user who accidentally deletes files or some other data disaster. This is where backups and disaster recovery come into play. Understanding the different options and why you need them is important for ensuring business continuity.
Wrapping up storage redundancy in Azure
Understanding the importance of storage redundancy as part of your overall business continuity plan is essential. Microsoft Azure replicates data in a storage account three times in the primary region by default. In addition, it has several options for ensuring data is available and redundant. For the AZ-104 exam, understand the different types of Azure storage redundancy, their characteristics and use cases and where these are configured.
Read More:
Microsoft Azure Administrator: AZ-104: Identity-Based Access for Azure Files – Part 26
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