# Backup Storage

Fixed-capacity hardware appliances buy immutability in vendor-sized increments. What that costs over a refresh cycle, and what changes when the storage layer is software-defined.

Two questions decide an immutable storage design: which recovery points need to be where, and how the team will prove a restore works. Plus three worked scenarios.

Immutable storage keeps data from being changed or deleted for a set period. How it differs from WORM, how deletion locks actually work, and what it does and does not protect against.

Explore storage solution for reliable backup repository. Compare XFS, reFS, object storage, and DPX vStor to optimize data protection, scalability, and performance for your 5-50TB dataset.⁠