Introduction to Azure Storage Services
Azure Storage is a set of cloud storage services provided by Microsoft as part of the Azure public cloud. It offers highly scalable object storage, file systems as a service, virtual disk storage, and specialized storage for messaging data and NoSQL datasets.
Azure Storage services include the following specific service offerings:
- Azure Blobs—elastically scalable object storage, supporting both text-based data and unstructured data such as images and video.
- Azure Files—managed file shared hosted on the cloud, which can be mounted by on-premise or cloud-based machines.
- Azure Queues—dedicated data store to enable fast, reliable messaging.
- Azure Tables—a NoSQL data store for key-value pairs, offering ease of use and high performance.
- Azure Disks—virtual hard disks that can be attached to Azure virtual machines (VM), based on block storage technology.
Note that different storage services have different authentication options:
- All storage services support shared key access
- All services support shared access signature (SAS) and Azure AD access, except Azure Files with SMB protocol
- Only Azure Files with SMB protocol supports on-premises Windows Active Directory access
- Only Azure Blobs supports public anonymous read access.
Types of Azure Storage Accounts
In the Azure cloud, all your storage services are organized in a unit called an Azure Storage Account. Your storage account allows you to track your costs and separate storage services belonging to different parts of the organization. There are several types of storage accounts, and the type you select determines storage features you can access and the Azure pricing model that applies to your storage.
Azure offers the following storage account types:
- General-purpose v2—provides blob storage, file storage, queue storage, and table storage. This is the default storage type recommended by Azure.
- Block Blob Storage account—provides premium performance for block blob storage. Use this account for workloads that have a high transaction throughput, a large number of small objects, or low storage latency.
- File Storage account—provides file storage only with enhanced performance. Use this account for high performance large scale applications that rely on file shares.
The following two storage account types are legacy, and Microsoft recommends not using them for new workloads:
- General-purpose v1 (legacy)—supports the same storage services as v1.
- Blob Storage account (legacy)—provides only blob storage.
Azure Storage Pricing
Several factors determine the price for Azure Storage. Here are the key elements in determining your Azure Storage fees:
- Total storage capacity—the basic factor determining Azure storage costs is the amount of data you store. Azure determines the total capacity by calculating the sum of all data in your persistent storage. This includes stored blobs, messages, files, metadata, and application data.
- Bandwidth—the transfer rate and the amount of data transferred from the storage account’s location. You can place cloud services and their corresponding storage at the same location to receive free bandwidth between computing and storage services. You only pay for access bandwidth when you access storage outside of its location.
Transactions—you are billed for the number of storage transactions or the number of representational state transfers (RESTs) executed on a storage account.
The unit cost you pay for storage will be determined by the following criteria:
- Region—the geographical location of your account.
- Account type—the type of Azure storage account you selected.
- Access tier—the data usage pattern you have specified, for example Hot or Cold storage tier.
- Replication—the number of data copies you maintain for your data.
Azure Storage Cost Optimization
Here are a few tips for optimizing your cost on Azure.
Select the Right Storage Tier
Azure Blob Storage provides three storage tiers, which provide a tradeoff between frequent access and storage cost:
- Hot Access—suitable for data that is frequently used for both read and write operations. Offers a higher storage cost but with low data access costs.
- Cool Access Tier—suitable for data that is accessed every 30 days or more. It provides lower storage costs but imposes a fee for access or deletion within 30 days of data creation, and higher access fees compared to the hot tier. A key benefit is that this tier enables instant access to data if required, making it effective for short-term backup and business continuity scenarios.
- Archive Access—intended for data that remains stored for at least six months and is rarely accessed. This tier imposes a fee for early deletion within six months of data creation. Data retrieval can take up to a few hours, depending on the priorities you define. This tier provides the lowest storage costs, but imposes the highest cost for data access and retrieval.
Select the Right Azure Files Storage Tier
Azure Files offers four storage tiers:
- Premium—provides SSD storage media, suitable for workloads that need low latency.
- Transaction optimized—supports workloads with high transaction throughput.
- Hot—standard storage enabling frequent access.
- Cool—standard storage with lower storage costs and a higher access cost, for files that are less frequently accessed.
Select the Right Performance Tier for Azure Disk Storage
Azure disks provide several performance tiers that allow you to adjust:
- I/O operations per second (IOPS)
- Data throughput
Selecting the most appropriate combination of the above requires analysis of application needs. Applications like database servers or online transaction processing (OLTP) need high IOPS, while applications that are computational in nature, such as batch processing, have lower requirements.
Note that you can change performance tier on Premium SSD disks temporarily, to meet special requirements, such as unusually high application load. When application load decreases, you can switch the disks to a lower performance tier.
Use Reserved Capacity
Azure Storage provides a pricing model known as reserved capacity, which lets you make a long-term commitment to storage resources and receive a substantial discount. Reserved capacity provides discounts of for:
- Block blob storage
- Azure Data Lake Storage Gen2
Reserved capacity requires a commitment of 1 or 3 years. Once you commit to reserved capacity, you must pay for the storage space, even if you do not currently use it.
The cost saving provided by reserved capacity depends on:
- Duration of reservation (3 year commitment provides a bigger discount)
- Total reserved storage capacity
- Access tier
- Type of redundancy
In this article, I explained the basics of Azure storage services, storage accounts, and the Azure storage pricing model. I also showed several ways you can easily reduce your Azure storage costs:
- Select the right storage tier—hot, cold, or archive, to optimize storage and data access costs according to your storage scenario.
- Select the right Azure Files storage tier—there are several tiers available to support high-throughput or low latency scenarios, as opposed to normal data access scenarios.
- Select the right performance tier for Disk Storage—like file storage, Azure disk storage also provides several performance tiers to support high throughput/low latency.
- Use reserved capacity—consider if you are using Azure Storage for the long term and commit to reserved capacity to receive significant discounts.
I hope this will be useful as you improve the cost efficiency of your cloud storage investment.
By Gilad David Maayan
Gilad David Maayan is a technology writer who has worked with over 150 technology companies including SAP, Samsung NEXT, NetApp and Imperva, producing technical and thought leadership content that elucidates technical solutions for developers and IT leadership.