Storage account overview
An Azure storage account contains all of your Azure Storage data objects: blobs, files, queues, and tables. The storage account provides a unique namespace for your Azure Storage data that's accessible from anywhere in the world over HTTP or HTTPS. Data in your storage account is durable and highly available, secure, and massively scalable.
To learn how to create an Azure Storage account, see Create a storage account.
Types of storage accounts
Azure Storage offers several types of storage accounts. Each type supports different features and has its own pricing model.
The following table describes the types of storage accounts recommended by Microsoft for most scenarios. All of these use the Azure Resource Manager deployment model.
| Type of storage account | Supported storage services | Redundancy options | Usage |
|---|---|---|---|
| Standard general-purpose v2 | Blob Storage (including Data Lake Storage1), Queue Storage, Table Storage, and Azure Files | Locally redundant storage (LRS) / geo-redundant storage (GRS) / read-access geo-redundant storage (RA-GRS) Zone-redundant storage (ZRS) / geo-zone-redundant storage (GZRS) / read-access geo-zone-redundant storage (RA-GZRS)2 |
Standard storage account type for blobs, file shares, queues, and tables. Recommended for most scenarios using Azure Storage. If you want support for network file system (NFS) in Azure Files, use the premium file shares account type. |
| Premium block blobs3 | Blob Storage (including Data Lake Storage1) | LRS ZRS2 |
Premium storage account type for block blobs and append blobs. Recommended for scenarios with high transaction rates or that use smaller objects or require consistently low storage latency. Learn more about example workloads. |
| Premium file shares3 | Azure Files | LRS ZRS2 |
Premium storage account type for file shares only. Recommended for enterprise or high-performance scale applications. Use this account type if you want a storage account that supports both Server Message Block (SMB) and NFS file shares. |
| Premium page blobs3 | Page blobs only | LRS ZRS2 |
Premium storage account type for page blobs only. Learn more about page blobs and sample use cases. |
1 Data Lake Storage is a set of capabilities dedicated to big data analytics, built on Azure Blob Storage. For more information, see Introduction to Data Lake Storage and Create a storage account to use with Data Lake Storage.
2 ZRS, GZRS, and RA-GZRS are available only for standard general-purpose v2, premium block blobs, premium file shares, and premium page blobs accounts in certain regions. For more information, see Azure Storage redundancy.
3 Premium performance storage accounts use solid-state drives (SSDs) for low latency and high throughput.
Legacy storage accounts are also supported. For more information, see Legacy storage account types.
The service-level agreement (SLA) for Azure Storage accounts is available at SLA for Storage Accounts.
Note
You can't change a storage account to a different type after it's created. To move your data to a storage account of a different type, you must create a new account and copy the data to the new account.
Storage account name
When naming your storage account, keep these rules in mind:
- Storage account names must be between 3 and 24 characters in length and may contain numbers and lowercase letters only.
- Your storage account name must be unique within Azure. No two storage accounts can have the same name.
Storage account endpoints
A storage account provides a unique namespace in Azure for your data. Every object that you store in Azure Storage has a URL address that includes your unique account name. The combination of the account name and the service endpoint forms the endpoints for your storage account.
There are two types of service endpoints available for a storage account:
- Standard endpoints (recommended). By default, you can create up to 250 storage accounts per region with standard endpoints in a given subscription. With a quota increase, you can create up to 500 storage accounts with standard endpoints per region. For more information, see Increase Azure Storage account quotas.
- Azure DNS zone endpoints (preview). You can create up to 5000 storage accounts per region with Azure DNS zone endpoints in a given subscription.
Within a single subscription, you can create accounts with either standard or Azure DNS Zone endpoints, for a maximum of 5250 accounts per region per subscription. With a quota increase, you can create up to 5500 storage accounts per region per subscription.
You can configure your storage account to use a custom domain for the Blob Storage endpoint. For more information, see Configure a custom domain name for your Azure Storage account.
Important
When referencing a service endpoint in a client application, it's recommended that you avoid taking a dependency on a cached IP address. The storage account IP address is subject to change, and relying on a cached IP address may result in unexpected behavior.
Additionally, it's recommended that you honor the time-to-live (TTL) of the DNS record and avoid overriding it. Overriding the DNS TTL may result in unexpected behavior.
Standard endpoints
A standard service endpoint in Azure Storage includes the protocol (HTTPS is recommended), the storage account name as the subdomain, and a fixed domain that includes the name of the service.
The following table lists the format for the standard endpoints for each of the Azure Storage services.
| Storage service | Endpoint |
|---|---|
| Blob Storage | https://<storage-account>.blob.core.windows.net |
| Static website (Blob Storage) | https://<storage-account>.web.core.windows.net |
| Data Lake Storage | https://<storage-account>.dfs.core.windows.net |
| Azure Files | https://<storage-account>.file.core.windows.net |
| Queue Storage | https://<storage-account>.queue.core.windows.net |
| Table Storage | https://<storage-account>.table.core.windows.net |
When your account is created with standard endpoints, you can easily construct the URL for an object in Azure Storage by appending the object's location in the storage account to the endpoint. For example, the URL for a blob will be similar to:
https://*mystorageaccount*.blob.core.windows.net/*mycontainer*/*myblob*
Azure DNS zone endpoints (preview)
Important
Azure DNS zone endpoints are currently in PREVIEW. See the Supplemental Terms of Use for Microsoft Azure Previews for legal terms that apply to Azure features that are in beta, preview, or otherwise not yet released into general availability.
When you create an Azure Storage account with Azure DNS zone endpoints (preview), Azure Storage dynamically selects an Azure DNS zone and assigns it to the storage account when it is created. The new storage account's endpoints are created in the dynamically selected Azure DNS zone. For more information about Azure DNS zones, see DNS zones.
An Azure DNS zone service endpoint in Azure Storage includes the protocol (HTTPS is recommended), the storage account name as the subdomain, and a domain that includes the name of the service and the identifier for the DNS zone. The identifier for the DNS zone always begins with z and can range from z00 to z50.
The following table lists the format for Azure DNS Zone endpoints for each of the Azure Storage services:
| Storage service | Endpoint |
|---|---|
| Blob Storage | https://<storage-account>.z[00-50].blob.storage.azure.net |
| Static website (Blob Storage) | https://<storage-account>.z[00-50].web.storage.azure.net |
| Data Lake Storage | https://<storage-account>.z[00-50].dfs.storage.azure.net |
| Azure Files | https://<storage-account>.z[00-50].file.storage.azure.net |
| Queue Storage | https://<storage-account>.z[00-50].queue.storage.azure.net |
| Table Storage | https://<storage-account>.z[00-50].table.storage.azure.net |
Important
You can create up to 5000 accounts with Azure DNS Zone endpoints per subscription. However, you may need to update your application code to query for the account endpoint at runtime. You can call the Get Properties operation to query for the storage account endpoints.
Azure DNS zone endpoints are supported for accounts created with the Azure Resource Manager deployment model only. For more information, see Azure Resource Manager overview.
To learn how to create a storage account with Azure DNS Zone endpoints, see Create a storage account.
About the preview
The Azure DNS zone endpoints preview is available in all public regions. The preview is not available in any government cloud regions.
To register for the preview, follow the instructions provided in Set up preview features in Azure subscription. Specify PartitionedDnsPublicPreview as the feature name and Microsoft.Storage as the provider namespace.
CNAME records, subdomains and IP addresses
Each storage account endpoint points to a chain of DNS CNAME records which eventually point to a DNS A record. The number of records and the subdomains that are associated with each record can vary between accounts and can depend on the storage account type and how the account is configured.
The storage account endpoint is stable and does not change. However, the CNAME records in a given chain can change and you won't be notified when a change occurs. If you host a private DNS service in Azure, then these changes can impact your configuration.
Consider the following guidelines:
The CNAME chain associated with a storage account endpoint can change without notice. Applications and environments should not take a dependency on the number of of CNAME records or the sub-domains that are associated with those CNAME records.
The A record's IP address that is returned by the DNS resolution of a storage account endpoint can change frequently.
The applications and operating systems should always honor the time-to-live (TTL) associated with the CNAME record. Caching the the value of the CNAME record beyond the TTL could lead to unintended behavior.
Migrate a storage account
The following table summarizes and points to guidance on how to move, upgrade, or migrate a storage account:
| Migration scenario | Details |
|---|---|
| Move a storage account to a different subscription | Azure Resource Manager provides options for moving a resource to a different subscription. For more information, see Move resources to a new resource group or subscription. |
| Move a storage account to a different resource group | Azure Resource Manager provides options for moving a resource to a different resource group. For more information, see Move resources to a new resource group or subscription. |
| Move a storage account to a different region | To move a storage account, create a copy of your storage account in another region. Then, move your data to that account by using AzCopy, or another tool of your choice. For more information, see Move an Azure Storage account to another region. |
| Upgrade to a general-purpose v2 storage account | You can upgrade a general-purpose v1 storage account or Blob Storage account to a general-purpose v2 account. Note that this action can’t be undone. For more information, see Upgrade to a general-purpose v2 storage account. |
| Migrate a classic storage account to Azure Resource Manager | The Azure Resource Manager deployment model is superior to the classic deployment model in terms of functionality, scalability, and security. For more information about migrating a classic storage account to Azure Resource Manager, see the "Migration of storage accounts" section of Platform-supported migration of IaaS resources from classic to Azure Resource Manager. |
Transfer data into a storage account
Microsoft provides services and utilities for importing your data from on-premises storage devices or third-party cloud storage providers. Which solution you use depends on the quantity of data you're transferring. For more information, see Azure Storage migration overview.
Storage account encryption
All data in your storage account is automatically encrypted on the service side. For more information about encryption and key management, see Azure Storage encryption for data at rest.
Storage account billing
Azure Storage bills based on your storage account usage. All objects in a storage account are billed together as a group. Storage costs are calculated according to the following factors:
- Region refers to the geographical region in which your account is based.
- Account type refers to the type of storage account you're using.
- Access tier refers to the data usage pattern you’ve specified for your general-purpose v2 or Blob Storage account.
- Capacity refers to how much of your storage account allotment you're using to store data.
- Redundancy determines how many copies of your data are maintained at one time, and in what locations.
- Transactions refer to all read and write operations to Azure Storage.
- Data egress refers to any data transferred out of an Azure region. When the data in your storage account is accessed by an application that isn’t running in the same region, you're charged for data egress. For information about using resource groups to group your data and services in the same region to limit egress charges, see What is an Azure resource group?.
The Azure Storage pricing page provides detailed pricing information based on account type, storage capacity, replication, and transactions. The Data Transfers pricing details provides detailed pricing information for data egress. You can use the Azure Storage pricing calculator to help estimate your costs.
Azure services cost money. Azure Cost Management helps you set budgets and configure alerts to keep spending under control. Analyze, manage, and optimize your Azure costs with Cost Management. To learn more, see the quickstart on analyzing your costs.
Legacy storage account types
The following table describes the legacy storage account types. These account types aren’t recommended by Microsoft, but may be used in certain scenarios:
| Type of legacy storage account | Supported storage services | Redundancy options | Deployment model | Usage |
|---|---|---|---|---|
| Standard general-purpose v1 | Blob Storage, Queue Storage, Table Storage, and Azure Files | LRS/GRS/RA-GRS | Resource Manager, classic1 | General-purpose v1 accounts may not have the latest features or the lowest per-gigabyte pricing. Consider using it for these scenarios:
|
| Blob Storage | Blob Storage (block blobs and append blobs only) | LRS/GRS/RA-GRS | Resource Manager | Microsoft recommends using standard general-purpose v2 accounts instead when possible. |
1 Beginning August 1, 2022, you'll no longer be able to create new storage accounts with the classic deployment model. Resources created prior to that date will continue to be supported through August 31, 2024. For more information, see Azure classic storage accounts will be retired on 31 August 2024.
Scalability targets for standard storage accounts
The following table describes default limits for Azure general-purpose v2 (GPv2), general-purpose v1 (GPv1), and Blob storage accounts. The ingress limit refers to all data that is sent to a storage account. The egress limit refers to all data that is received from a storage account.
Microsoft recommends that you use a GPv2 storage account for most scenarios. You can easily upgrade a GPv1 or a Blob storage account to a GPv2 account with no downtime and without the need to copy data. For more information, see Upgrade to a GPv2 storage account.
Note
You can request higher capacity and ingress limits. To request an increase, contact Azure Support.
| Resource | Limit |
|---|---|
| Maximum number of storage accounts with standard endpoints per region per subscription, including standard and premium storage accounts. | 250 by default, 500 by request1 |
| Maximum number of storage accounts with Azure DNS zone endpoints (preview) per region per subscription, including standard and premium storage accounts. | 5000 (preview) |
| Default maximum storage account capacity | 5 PiB 2 |
| Maximum number of blob containers, blobs, directories and subdirectories (if Hierarchical Namespace is enabled), file shares, tables, queues, entities, or messages per storage account. | No limit |
Default maximum request rate per general-purpose v2 and Blob storage account in the following regions:
|
40,000 requests per second2 |
| Default maximum request rate per general-purpose v2 and Blob storage account in regions that aren't listed in the previous row. | 20,000 requests per second2 |
Default maximum ingress per general-purpose v2 and Blob storage account in the following regions:
|
60 Gbps2 |
| Default maximum ingress per general-purpose v2 and Blob storage account in regions that aren't listed in the previous row. | 25 Gbps2 |
| Default maximum ingress for general-purpose v1 storage accounts (all regions) | 10 Gbps2 |
Default maximum egress for general-purpose v2 and Blob storage accounts in the following regions:
|
200 Gbps2 |
| Default maximum egress for general-purpose v2 and Blob storage accounts in regions that aren't listed in the previous row. | 50 Gbps2 |
| Maximum egress for general-purpose v1 storage accounts (US regions) | 20 Gbps if RA-GRS/GRS is enabled, 30 Gbps for LRS/ZRS |
| Maximum egress for general-purpose v1 storage accounts (non-US regions) | 10 Gbps if RA-GRS/GRS is enabled, 15 Gbps for LRS/ZRS |
| Maximum number of IP address rules per storage account | 400 |
| Maximum number of virtual network rules per storage account | 400 |
| Maximum number of resource instance rules per storage account | 200 |
| Maximum number of private endpoints per storage account | 200 |
1 With a quota increase, you can create up to 500 storage accounts with standard endpoints per region. For more information, see Increase Azure Storage account quotas.
2 Azure Storage standard accounts support higher capacity limits and higher limits for ingress and egress by request. To request an increase in account limits, contact Azure Support.