3-2-1-1-0

The 3-2-1-1-0 backup strategy is a data protection framework that extends the classic 3-2-1 rule by adding an immutable copy and a zero-error verification step. Discussions on WindowsForum.com emphasize diversifying cloud storage across multiple providers to avoid single points of failure, as recent incidents with OneDrive and AWS have shown. The approach recommends maintaining three copies of data on two different media types, with one offsite copy, plus an immutable backup that cannot be altered or deleted, and automated integrity checks to ensure zero errors. This strategy is particularly relevant for Windows users managing critical data, offering a robust defense against ransomware, accidental deletion, and provider outages.