321 Method
3 copies (versions count) ( Acheived with versioning/retention in the Appliance based backup, and the Direct to cloud backup )
Stored on 2 storage devices \ media
1 of which is cloud ( 1 airgapped and/or immutable copy )
How often are we able to conduct a full backup test?
Azure
Azure Backup gives you diverse options such as soft delete, stop backup and delete data or retain data if you need to stop backups at any time. To protect critical operations, you can add Multi-User Authorization (MUA) that adds additional layer of protection by using an Azure resource called Azure Resource Guard.