About immutable storage support for Azure blob storage
NetBackup 10.0 and later versions support the immutable storage for Azure Blob Storage to store the backup data. For more information about Azure immutable storage, see Store business-critical blob data with immutable storage.
You can use one of the following time-based retention policies for immutable blob data:
Locked policy
You cannot overwrite or delete the data that is protected using the locked policy for the defined retention period. Once you set a retention period for the data storage, you can extend it but cannot shorten it.
Unlocked policy
You cannot overwrite or delete the data that is protected using the locked policy for the defined retention period. Once you set a retention period for the data storage, you can extend, shorten, or delete it.