WORM Storage in Microsoft Azure

The feature is available in all Azure public regions. Through configurable policies, users can keep Azure Blob storage data in an immutable state where Blobs can be created and read, but not modified or deleted.

What is WORM storage?

WORM just means that the data written to the storage media is immutable. No changes can occur. A file can be read as many times as necessary, but it cannot be overwritten, deleted, or modified in any way.

Typical applications include:

• Regulatory compliance: Immutable storage for Azure Blobs is designed to help financial institutions and related industries address SEC 17a-4(f), CFTC 1.31©-(d), FINRA etc. A technical whitepaper with details on how the feature addresses these regulatory requirements is downloadable now via the Service Trust Portal. The Azure Trust Center contains detailed information about our compliance certifications.
• Secure document retention: Users receive maximum data protection as the immutable storage feature for Azure Blobs service ensures that data cannot be modified or deleted by any user including those with account administrative privileges.
• Legal hold: Immutable storage for Azure Storage Blobs enables users to store sensitive information critical to a litigation, criminal investigation, and more in a tamper-proof state for the desired duration.

Immutable storage for Azure Storage Blobs enables:

• Time-based retention policy support: Users set policies to store data immutably for a specified interval of time.
• Legal hold policy support: When the retention interval is not known, users can set legal holds to store data immutably until the legal hold is cleared.
• Support for all Blob tiers: WORM policies are independent of the Azure Blob Storage tier and will apply to all the tiers, hot, cool and archive. This allows customers to store the data in the most cost-optimized tier for their workloads while maintaining the data immutability.
• Blob Container level configuration: Immutable storage for Azure Storage Blobs allows users to configure time-based retention policies and legal hold tags at the container level. Users can create time-based retention policies, lock policies, extend retention intervals, set legal holds, clear legal holds etc. through simple container level settings. The policies apply to all the Blobs in the container, both existing and new Blobs.