Using the Windows Azure Storage Services
The Windows Azure storage services provide storage for binary and text data, messages, and structured data in Windows Azure. The storage services include:
- The Blob service, for storing binary and text data
- The Queue service, for storing messages that may be accessed by a client
- The Table service, for structured storage for non-relational data
- Windows Azure drives, for mounting an NTFS volume accessible to code running in your Windows Azure service
Programmatic access to the Blob, Queue, and Table services is available via the Windows Azure Managed Library and the Windows Azure storage services REST API. See these sections for detailed reference information:
For conceptual information about using blobs, queues, and tables, see these sections:
About Windows Azure Drives
A Windows Azure drive acts as a local NTFS volume that is mounted on the server’s file system and that is accessible to code running in a role. The data written to a Windows Azure drive is stored in a page blob defined within the Windows Azure Blob service, and cached on the local file system. Because data written to the drive is stored in a page blob, the data is maintained even if the role instance is recycled. For this reason, a Windows Azure drive can be used to run an application that must maintain state, such as a third-party database application.
The Windows Azure Managed Library provides the CloudDrive class for mounting and managing Windows Azure drives. The CloudDrive class is part of theMicrosoft.WindowsAzure.StorageClient namespace. See the Windows Azure Managed Library Reference for more information.
Once a Windows Azure drive has been mounted, you can access it via existing NTFS APIs. Your Windows Azure service can read from and write to the Windows Azure drive via a mapped drive letter (e.g., X:\).
For details on getting started with Windows Azure drives, see the Windows Azure Drives white paper.
Support for Windows Azure Drives was introduced with Windows Azure Guest OS 1.1 (Release 201001-01). To deploy a service that utilizes Windows Azure Drives, you must deploy to Windows Azure Guest OS 1.1 (Release 201001-01). If you deploy your service to an earlier version, your service may throw a CloudDriveException with the error stringERROR_UNSUPPORTED_OS when it attempts to call methods that operation on Windows Azure Drives. For more information, see Windows Azure Guest OS Releases and SDK Compatibility Matrix and How to Configure Operating System Versions. |
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